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The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop (2021)

Chapter: 2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence

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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
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2

Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence

The workshop featured two keynote addresses delivered during a session moderated by Matthew Zahn, medical director at the Orange County Health Care Agency’s Division of Epidemiology and Assessment. Ann Lindstrand, Expanded Programme on Immunization (EPI) coordinator at the Department of Immunization and Biologics at the World Health Organization (WHO), described the global impacts of the coronavirus disease 2019 (COVID-19) pandemic on vaccination uptake (demand-side factors) and access (supply-side factors). She discussed findings from various global efforts to collect data about the pandemic’s effects as well as efforts under way to address numerous vaccine-related concerns that have come to the fore during the pandemic. Saad B. Omer, director of the Yale Institute for Global Health, explored the global state of vaccine uptake and potential strategies to enhance that uptake. He discussed early warnings related to the COVID-19 pandemic, trends and factors contributing to vaccine hesitancy, and approaches for promoting acceptance of forthcoming COVID-19 vaccines.

IMPACT OF THE COVID-19 PANDEMIC ON IMMUNIZATION SERVICES AND ACCESS

Presented by Ann Lindstrand, World Health Organization

Lindstrand described how the COVID-19 pandemic has disrupted immunization services and interrupted essential health services worldwide (see Box 2-1). She highlighted pandemic-related factors affecting both the

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
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supply chain and the demand for routine immunizations, as well as the indirect effects of service disruptions. She also discussed the forthcoming challenges involved in the large-scale administration of a vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, while simultaneously carrying out catch-up activities.

Rapid Assessment of Continuity of Essential Health Services

Lindstrand presented preliminary results from WHO’s Rapid Assessment of Continuity of Essential Health Services during the COVID-19 pandemic, a comprehensive survey of the pandemic’s impact on 25 essential health services across the life course that was conducted with the following aims:1 (1) to understand the extent of service disruptions across all services; (2) to assess prevailing mitigation strategies for maintaining services; and (3) to identify priorities and targets for technical assistance. Lindstrand explained that the methodology involved sending the online survey of essential health services, including vaccination, to all countries in the world on May 15, 2020, to be completed by July 6, 2020. A total of 103 countries responded, with national ministry of health (MOH) counterparts submitting responses directly or with facilitation through WHO country offices.2

Survey data indicate that routine immunization, provided both via outreach and at fixed health facilities, are some of the most negatively affected

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1 More information about the pulse survey on the continuity of essential health services during the COVID-19 pandemic is available at https://www.who.int/publications/i/item/WHO2019-nCoV-EHS_continuity-survey-2020.1 (accessed November 4, 2020).

2 Response rates by region: WHO South-East Asia Region (82 percent); WHO Western Pacific Region (69 percent); WHO African Region (64 percent); WHO Regional Office for Europe (62 percent); WHO Regional Office for the Eastern Mediterranean (59 percent).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

health services during the COVID-19 pandemic, said Lindstrand. Routine immunization outreach has been the third-most affected health service, after dental and rehabilitation services, with partial or complete service disruption reported in 70 percent of the 89 responding countries. In 60 percent of 103 responding countries, routine immunization services provided at fixed health facilities have reported disruptions. All of the 25 essential health services included in the survey had countries reporting both partial and complete disruptions during the COVID-19 pandemic, with disruption rates ranging from 19 to 77 percent of responding countries. Lindstrand maintained that achieving a “new normal” after the pandemic will likely require working toward a comprehensive package of health services with greater horizontal integration of services that are currently administered vertically.

Pulse Poll on Immunization Disruptions

WHO also developed a survey in collaboration with the United Nations Children’s Fund (UNICEF); Gavi, the Vaccine Alliance; the U.S. Centers for Disease Control and Prevention (CDC) Global Immunization Division; the Sabin Vaccine Institute’s Boost Initiative; and the International Vaccine Access Center at Johns Hopkins to monitor the global effects of the COVID-19 pandemic on immunization services—particularly during May 2020. Lindstrand noted that this poll was not intended to replace other immunization data-collection efforts but to take a quick snapshot of the impact of the COVID-19 pandemic across the world. The co-developers shared the poll through their networks, rather than directly contacting MOHs. A total of 260 respondents from 82 countries and territories completed the survey during the polling period of June 5–20, 2020. The respondents came from three distinct organization categories: (1) MOHs; (2) WHO, UNICEF, and Gavi; and (3) other types of organizations, including public and private health facilities, nongovernmental organizations, faith-based organizations, and National Immunization Technical Advisory Groups.3 All six WHO regions were represented in both national and subnational survey responses, with the majority of respondents coming from the WHO African Region.

Lindstrand noted that of the 82 respondents, 61 represented national-level vaccination efforts, while 21 represented efforts at a subnational level. Of the national-level respondents, 44 percent indicated disruptions in fixed-post immunizations. The most affected regions in May 2020 were those administered by the WHO Regional Office for the Americas (AMRO)

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3 National Immunization Technical Advisory Groups are independent groups of experts that advise national governments on issues related to immunizations and vaccines. More information is available at https://www.who.int/immunization/sage/national_advisory_committees/en (accessed April 2, 2021).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

and the WHO Regional Office for South-East Asia, with 75 percent and 71 percent of respondents, respectively, reporting disruptions. Lindstrand explained that outreach vaccination activities were more disrupted than fixed-post immunization services.4 In looking at the 65 unique nations represented in the outreach response data, 58 percent reported service disruptions and 11 percent indicated suspension of outreach activities. For the region administered by the WHO Regional Office for Africa (AFRO), the percentage of nations indicating outreach disruptions in May 2020 was as high as 86 percent.

Disruptions in Immunization Availability

To understand global-level vaccination service disruptions, WHO researchers explored possible factors related to the COVID-19 pandemic, said Lindstrand. The most commonly reported reason was low availability of personal protective equipment (PPE) for health care workers, with 49 percent of national and subnational respondents indicating this as a contributing factor. Other disruption factors include low availability of health care workers (43 percent), travel restrictions (40 percent), limited availability of vaccines or immunization supplies such as syringes (24 percent), and national policies related to immunization services (15 percent). Lindstrand noted AMRO and AFRO particularly had challenges in accessing PPE. AMRO and the WHO Regional Office for the Western Pacific indicated the highest levels of lack of availability of health care workers because of employees being diverted for pandemic response.

Immunization Demand Disruptions

Lindstrand described a substantial decrease in reported demand of vaccination services, with 73 percent of the 62 responding nations indicating disruption in demand. This was most significant in AFRO, with 89 percent of respondents reporting demand disruptions, but was present in all six regions. Lindstrand asserted that survey data indicate this decrease was not caused by public concern about routine immunizations but rather due to ramifications of the COVID-19 pandemic. The top user concern was risk of increased exposure to COVID-19 by coming to a facility for a vaccination, cited by 48 percent of respondents.5 Additional reasons included being unable to travel to a vaccination facility because of limited public transport, lockdowns, or physical distancing policies (33 percent); user uncertainty as to whether routine

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4 More information about disruptions to vaccination caused by COVID-19 is available at https://www.who.int/immunization/monitoring_surveillance/immunization-and-covid-19/en (accessed November 4, 2020).

5 Percentages are weighted by number of respondents per country.

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

vaccination services remained available (10 percent); and user concern about increasing risk of exposure to COVID-19 by leaving their home (6 percent).

Addressing Disruptions in Immunization Demand

The survey assessed whether plans have been put in place to address the trend of decreasing demand, Lindstrand said. About 85 percent of the 54 countries that responded to this portion of the survey reported having plans to increase vaccine demand. The majority of respondents (82 percent) reported efforts involving awareness building, community engagement, and social mobilization. Tactics to increase awareness include mass media (e.g., television, radio, newspaper); engagement through community leaders, including religious leaders; and house-to-house outreach to encourage caregivers to continue their child’s immunization schedule. Enhanced in-home service outreach efforts were reported by 13 percent of respondents, with the intention of mitigating concerns about crowding at health facilities. Other plans included increased infection prevention and control measures, training of health care workers, and research into reasons behind missed vaccinations. Lindstrand added that support from Gavi, WHO, UNICEF, and many other organizations has increased preventive measures, but this is not sufficient to fully address the downward trend in demand.

The survey also assessed concerns about rumor and misinformation regarding COVID-19 and immunization. Approximately 74 percent of respondents reported that their countries have been tracking rumors and misinformation. The channels being used to monitor misinformation include mainstream media (68 percent of respondents), digital media (65 percent), community reporting (55 percent), and other channels (4 percent). The monitoring emphasis on different channels varied by WHO region. Determining responses to different rumors is a current area of discussion, Lindstrand added.

Efforts to vaccinate groups of persons who may have missed their vaccines were assessed. The majority of respondents (77 percent) indicated their country, province, or district had been planning group vaccination activities. Planned efforts include outreach activities (64 percent); fixed routine immunization (59 percent); periodic intensification of routine immunization (PIRI) via “child health/vaccination days,” “health weeks,” or other efforts (40 percent); and supplemental immunization activity (28 percent). Lindstrand said WHO regional offices are supporting countries in determining how to reach those who missed immunizations during the COVID-19 pandemic. These catch-up plans have already been put into action in some areas.6

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6 More information about WHO guidance for planning and implementing catch-up vaccination is available at https://www.who.int/immunization/programmes_systems/policies_strategies/WHO_Catch-up_guidance_working_draft_11.08.20.pdf?ua=1 (accessed November 4, 2020).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

Lindstrand emphasized that demand-related issues stem both from family concerns and from the health care system. Family concerns include lockdowns, distancing policies, risk of increased exposure to COVID-19 during routine immunizations, and the safety of public transport. Lack of awareness about the continuity of routine vaccination services and fears related to misinformation and rumors also negatively affect family immunization demand. According to Lindstrand, health care system issues include health workers lacking motivation or being diverted toward the COVID-19 pandemic response, having safety fears about their own susceptibility to COVID-19, and concerns related to pandemic response and lockdown. She noted that some factors affect both family-related and staff-related decreases in demand. These include lack of PPE and training in infection prevention and control, lack of vaccine resources, capacity limitations, and vaccine delivery suspension caused by the COVID-19 pandemic. Lindstrand said the lack of PPE has made it especially difficult for parents and health care workers to participate in effective immunization services.

Not only has the COVID-19 pandemic been affecting routine immunizations, it has also been causing disruptions in other ongoing health services around the world, said Lindstrand. For example, measles surveillance, notification, and case investigations have been suspended or disrupted in many countries. As potential causes of these service interruptions, she cited lack of equipment, difficulty in obtaining supplies, and workforce shortages caused by diverting health care workers and surveillance monitoring officers toward the pandemic response. Additionally, 56 countries reported postponing at least one vaccine-preventable disease immunization campaign because of the COVID-19 pandemic; the majority of vaccines affected by these disruptions were related to measles or polio. WHO has estimated that 178 million people may be at risk of missing measles shots in 2020 because of decreased campaigns and outreach. Relative differences in administered doses of diphtheria, tetanus, and pertussis vaccine dose 3 in 2019 versus 2020 reveal steep decreases in March and April across WHO regions (see Figure 2-1). Lindstrand explained these data illustrate the severity of the coverage decrease, the ramifications of which will depend on whether countries can effectively increase efforts to reach those who have missed immunizations.

Mitigating the Effects of the COVID-19 Pandemic

The indirect supply-side and demand-side effects of the COVID-19 pandemic are also worrisome, said Lindstrand. A modeling study looked at the indirect effects of the COVID-19 pandemic on maternal and child mortality in 118 low- and middle-income countries to estimate the additional maternal and under age 5 child deaths associated with disruptions to the health system and decreased access to food (Roberton et al., 2020). Accounting for factors

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
Image
FIGURE 2-1 Relative differences in diphtheria, tetanus, and pertussis vaccine dose 3 (2019 versus 2020).
NOTES: Countries reporting by WHO region. AFR = WHO African Region; AMR = WHO Region of the Americas; EMR = Eastern Mediterranean Region; SEAR = South-East Asia Region; WPR = Western Pacific Region.
SOURCES: Lindstrand presentation, August 17, 2020; administrative data received from member states until July 6, 2020 (data likely incomplete for 2020).

affecting both provision and use of health services, the study presents three possible scenarios featuring varying levels of reduction of essential maternal and child health interventions. All scenarios indicate that postponing immunizations will result in a substantial number of additional child deaths per month: tetanus toxoid vaccination (1,910–6,610 deaths); measles vaccine (1,030–3,260 deaths); diphtheria, tetanus, and pertussis vaccine (950–2,890 deaths); Haemophilus influenzae type B vaccine (560–1,720 deaths); and pneumococcal conjugate vaccine (460–1,410 deaths).

In an effort to mitigate these indirect effects, WHO has been issuing guidance to support countries (WHO, 2020a,b). This has included guiding principles on maintaining immunization services during the COVID-19 pandemic for all countries, which Lindstrand noted prioritizes immunization as a core health service. Although countries were initially advised to temporarily suspend mass vaccination campaigns, WHO has backed away from this advice if the vaccine campaigns can be implemented safely. The guidance encourages maintaining ongoing routine immunization delivery with protection measures against COVID-19 in place. Furthermore, she added that

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

countries are urged to plan for catch-up vaccination as early as possible and implement catch-up activities in parallel with ongoing services. In August 2020, WHO released guidance regarding the planning and implementation of catch-up vaccination programs that addresses the following components:

  • Strategies for catch-up vaccination;
  • Vaccines and supplies;
  • Data systems, tools, recording, and reporting;
  • Health worker knowledge and practice; and
  • Communications and community engagement.7

Lindstrand noted that this guidance includes information on how to properly organize safe immunization sessions during the COVID-19 pandemic.

How to implement the new COVID-19 vaccines quickly and safely continues to be a major concern, said Lindstrand. A balance will need to be struck between administering 2 billion doses of a new vaccine and continuing uptake of routine immunizations. She suggested that achieving a high level of COVID-19 vaccine uptake will involve building public knowledge and awareness while enhancing confidence; anticipating risks and communicating them effectively and early; and informing national policy making, planning, and implementation.

Catch-up efforts to increase the uptake of routine immunizations will involve embedding the value of vaccination in all strategies and messages (including in the implementation of the new COVID-19 vaccines), ensuring that planning is informed by the latest evidence and data, and building capacity at local levels to tailor and implement demand management strategies.

GLOBAL VACCINE CONFIDENCE AND STRATEGIES TO ENHANCE UPTAKE

Presented by Saad B. Omer, Yale Institute for Global Health

Omer presented three warnings he issued at the outset of the COVID-19 pandemic in the United States, and then he explored the state of global vaccine hesitancy. He presented data that showed how attempting to correct misinformation can backfire, and he introduced an approach to addressing vaccine hesitancy based on the Moral Foundations Theory.

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7 More information about WHO guidance for planning and implementing catch-up vaccination is available at https://www.who.int/immunization/programmes_systems/policies_strategies/WHO_Catch-up_guidance_working_draft_11.08.20.pdf?ua=1 (accessed November 4, 2020).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

Three Warnings at the Outset of the COVID-19 Pandemic

Omer’s opinion piece “Is America Ready for Another Outbreak?” was published in The New York Times on January 23, 2020, 2 days after CDC confirmed the first case of COVID-19 in the United States (Omer, 2020). Omer said that at the time of publication, experts were already seeing concerning signs (although they had not yet given the syndrome its official name of COVID-19), and these concerns spurred him to write the piece. Even though he could not have predicted the height of eventual case and mortality burdens, he was concerned about the state of preparedness. To that end, he issued three warnings and suggested strategies that the country should take in preparing for and responding to the COVID-19 outbreak.

The first warning was to let the scientists lead the response effort. Omer explained that communications research, pandemics research, and experience with pandemics all suggest that messaging from an authoritative, scientific perspective is more trusted than information from other sources. A pandemic is a dynamic situation with a rapidly evolving evidence base; thus, the response effort depends on the ability to synthesize and assimilate emerging and evolving evidence and translate that evidence into action. He added that well-respected scientists and public health professionals are best able to clearly communicate that evidence to the public—including uncertainty about the evidence.

Secondly, Omer warned against providing false assurances to the public during a pandemic. Evidence from public health emergencies, including outbreaks, indicate that public authorities and political leaders tend toward providing assurances. This instinct is understandable and may help to calm the public in the short term. However, over the longer term, assurances that are not supported by evidence can lead to the loss of public trust and can hamper the ability to communicate mass recommendations that may be challenging.

Thirdly, Omer warned about the consequences of scientific and public misinformation. He said that at the time of his opinion piece, misinformation was already spreading about COVID-19. The pandemic has fueled the propensity of researchers to share output early on, resulting in an explosion in preprint publications, he added. Preprints can be a useful tool when sharing nascent information in a rapidly evolving data landscape. However, Omer contended, when information has not gone through the critique and quality control measures involved in peer review, it can exacerbate the issue of premature data release muddling public understanding. He described his three warnings as prescient in terms of their implications for communicating about the COVID-19 pandemic and specifically about COVID-19 vaccines.

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

Addressing Vaccine Hesitancy

Vaccine hesitancy is a widespread, heterogeneous phenomenon, said Omer. According to his research, 2013 data suggest that some level of vaccine hesitancy—or “soft demand”—is present in most countries worldwide. The Vaccine Confidence Project conducted a 2019 survey that asked respondents whether they agreed with the statement “I think vaccines are safe.”8 The responses by country were heterogeneous, with hot spots of vaccine hesitancy in Eastern Europe, France, Japan, South Korea, and other nations. Not all attitudes lead to actual vaccine refusal, he noted, but attitudes should be monitored at the global level on an ongoing basis.

Potential Backfire Effect of Correcting Misinformation

When confronted with patients citing misinformation about vaccines, it is the logical and intuitive response of clinicians to correct such misinformation. However, Omer pointed out that what little evidence there is on the usefulness of correcting misinformation is nuanced and multidimensional. For instance, a 2015 study on the limitations of fact-based messaging measured the effect of this approach by studying parents coming to doctors’ offices for pediatric vaccinations (Nyhan and Reifler, 2015). Parents were divided into three groups based on their baseline attitudes toward vaccines: most favorable, somewhat favorable, and least favorable. Various interventions were conducted and measured, including images, narratives, risks, correction, and a control group. The results of this study revealed a “backfire effect of correcting information” in which parents who were least favorable toward vaccines had a lower propensity toward vaccination after the intervention. Omer noted that the data are nuanced—not all myth correction has produced the backfire effect—but using the correction of misinformation as the go-to intervention strategy warrants caution.

Recognizing Underlying Values

In looking for more effective strategies to address vaccine hesitancy, Omer and colleagues have looked at people’s underlying values. According to the Moral Foundations Theory,9 everyone has underlying values that operate somewhat similarly to taste buds. That is, the five primary tastes (i.e., bitter, salty, sweet, sour, umami/savory) are experienced through the permutation of the taste buds evoked by a food, but also via an individual’s

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8 More information about the Vaccine Confidence Project is available at www.vaccineconfidence.org (accessed November 4, 2020).

9 More information about the Moral Foundations Theory is available at https://moralfoundations.org (accessed November 8, 2020).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

underlying propensity to certain flavors (Chandrashekar et al., 2006). The Moral Foundations Theory identifies six “moral taste buds” that the authors of the theory call moral foundations (Haidt, 2012). These six moral foundations are care/harm, fairness/cheating, loyalty/betrayal, authority/subversion, purity/degradation, and liberty/oppression. The six foundations are emphasized differently in various populations, he noted, and stimuli can evoke different combinations of these values.

Omer explained how the Moral Foundations Theory specifies each value and makes it measurable, allowing the values to inform interventions. The moral foundation of care/harm is the most hardwired, he noted. Care/harm creates the urge to protect lives and fuels the desire to cuddle cute animals. Fairness/cheating is exhibited in the “golden rule” common in most ethics systems and underlies people’s inherent reactions to unfair situations. Loyalty/betrayal is a foundation for national pride, sports fandom, and other forms of manifesting allegiance; it also underlies feelings of betrayal when loyalty is lacking. Authority/subversion accounts for why some people are more submissive to authority than others. Purity/degradation can be a religious-valence-based concept or a secular concept (e.g., when people do not want to put toxins in their bodies). Liberty/oppression is also a common value, he added.

Omer and colleagues conducted a study in the United States that demonstrated for the first time that vaccine decisions can be value-based decisions (Amin et al., 2017). By assessing vaccine hesitancy and the values of authority, fairness, harm, loyalty, purity, and liberty, they found that people who were more likely to be accepting of vaccines also tended to emphasize the authority foundation and defer to their physicians’ recommendations. Those who were most hesitant to have vaccines tended to emphasize purity and liberty.

Appealing to Values to Change Behaviors

Omer explored how this understanding of vaccine behavior as a set of value-based decisions can be operationalized by appealing to—rather than attempting to change—people’s values. Recently, Omer and colleagues looked at whether purity and disgust can be used to increase human papillomavirus (HPV) infection vaccination (James et al., 2020). Many countries have poor vaccine coverage in teens aged 11–15, which puts them at increased risk of infection in college, when sexual activity tends to increase and vaccines are less likely to be effective. The primary approach used to increase acceptance of HPV vaccines is emphasizing the impact on cancer. Although this approach is appropriate, there are noted substantial limitations to the use of cancer-based and severity-based messages for HPV in this college age group, he noted. In a randomized controlled trial, participants

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

were presented with images and a narrative about genital warts that emphasized how the disease can violate purity values. Participants in the treatment arm were about 20 percent more likely to receive the HPV vaccine within the subsequent 6 months than those in the control arm, said Omer.

Narratives Over Statistics

Omer described how narratives of disease severity can resonate more effectively than statistical probabilities. He noted that humans are “excellent linguists but poor statisticians,” as demonstrated by the difficulty people have in conceptualizing statistics in their perception of risk. For example, even experts may not be able to comprehend the difference between a risk of 1 in 10 million versus 1 in 100 million in a visceral way. One way to think about this phenomenon is by focusing on availability heuristics, which hold that “people judge the probability of events by the ease with which instances could be brought to mind” (Tversky and Kahneman, 1973). Therefore, the actual frequency of an event does not necessarily affect perception of probability. For instance, people tend to be more afraid of flying than of driving even through the actual risk of the latter is greater. This may be attributed to the vividness with which plane crashes are reported, while car crashes are treated as a norm unless they stand out markedly from the usual pattern, he suggested.

In a 2013 study examining the effect of statistics on parents’ vaccination decisions, parents were presented with different conditions and the associated risks of vaccination versus non-vaccination (Sadique et al., 2013). For example, participants were told the chance of having a vaccine-associated side effect is 20 in 100,000, whereas the chance of contracting the disease if not immunized is 20,000 in 100,000—representing a 1,000-fold difference. The researchers manipulated the conditions to see if this had an effect on vaccine acceptance. Even though the risk of an unvaccinated child contracting a disease is much higher than having a vaccine-associated adverse event, presenting those relative risks to parents did not affect vaccine hesitancy. Rather, it was the perceived severity of the disease or adverse event that affected vaccination acceptance. Furthermore, parents tended to exhibit omission bias, anticipating more regret from a decision to vaccinate than not to vaccinate, because they conceived of vaccination as active and non-vaccination as passive. Omer suggested approaching vaccine hesitancy by framing vaccination as a routine act and non-vaccination as an active decision, rather than the converse; the limitations to this approach could potentially be addressed with a focus on values.

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

Promoting COVID-19 Vaccine Acceptance in the United States

To look at acceptance of a COVID-19 vaccine in the U.S. population, Omer and colleagues administered a survey and found that nearly 70 percent of people were outright accepting or more accepting of a vaccine (Malik et al., 2020).10 Those with more vaccine hesitancy were not necessarily rejecting vaccines that prevent COVID-19; rather, they had concerns at that point in time, which made them uncertain as to whether they would eventually accept the vaccine. Furthermore, Omer and colleagues found vaccine acceptance varied by region in the U.S. population (Malik et al., 2020). Slightly more than half of U.S. states had acceptance rates ranging from 60 to 75 percent. Segments of the U.S. Midwest and Southwest regions had the highest rates of vaccine acceptance (> 75 percent) while the Southeast region had lower rates of acceptance (50–60 percent). The lowest acceptance rates (< 50 percent) were in the Great Lakes region. Omer and colleagues then developed and evaluated a predictive model based on commonly available demographic data, which is the subject of ongoing research to examine whether interventions can be targeted more directly to small population groups.11

Contending with Myths

Omer noted that there are times when correcting a myth is unavoidable. An approach developed in 2011 to address climate change communication suggests that instead of emphasizing the myth itself, efforts should focus on asserting that it is a myth (Cook and Lewandowsky, 2011). An example of this approach provided by Omer would be replacing inappropriate headlines such as “Does MMR Vaccine Cause Autism?” and “Are COVID-19 Vaccines Unsafe?” with headlines such as “The Myth of MMR Being Associated with Autism Refuses to Go Away,” Omer suggested. The clear assertion that the information is incorrect can be bolstered with factual evidence pointing out falsity. Ultimately, the myth should be replaced with the best alternative explanation to prevent the dispelled myth from reemerging in people’s minds. Omer closed by presenting an overview of the current evidence about effective strategies to address vaccine hesitancy (see Box 2-2).

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10 For more information on Omer’s survey work regarding COVID-19 vaccines and public opinion, see https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(20)30239-X/fulltext (accessed March 2, 2021) and https://pubmed.ncbi.nlm.nih.gov/33390295 (accessed March 2, 2021).

11 This research had been accepted for publication only days prior to the time of the workshop, so it was not discussed any further. For the fully published results, see https://europepmc.org/article/MED/32838242 (accessed March 2, 2021).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
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DISCUSSION

Addressing Vaccine Hesitancy Related to Development Speed

Zahn asked Omer and Lindstrand about approaches to address fears and vaccine hesitancy that are specifically related to the speed at which the COVID-19 vaccines are being developed, tested, and approved. Omer replied that the first step is to ensure these vaccines are developed using mainstream pathways. He elaborated that while it will be appropriate and necessary to find efficiencies in the process, the vaccine development time-line ought to be sped up by making the process more efficient rather than by skipping critical steps. To illustrate how efficiencies could be identified, he noted that the mainstream vaccine community views phase 3 trials as the cornerstone of evaluating efficacy and safety in the population. Often, this is conducted by evaluating large samples and making calculations based on the number of disease or infection incidents (referred to as “events”) that occur in the intervention arm versus the control arm. One method is to conduct large-scale trials with a large enough sample size to capture events over a shorter time frame with equivalent statistical significance. This approach has been adopted in COVID-19 vaccine trials, Omer noted, and vaccine developers have been able to find efficiencies to speed up the process without undermining the reliability of clinical data or information.12 Omer suggested communicating both the “why” and the “how” of efficiency implementation in the COVID-19 vaccine development process as a way to reassure the public that corners are not being cut.

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12 This is an abbreviated explanation of the vaccine trial design for COVID-19. More detail can be found at https://media.tghn.org/articles/Vaccine_Efficacy_V1.0_7_May_20.pdf (accessed December 17, 2020).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

Strategies for Tracking Vaccinations Around the World

Zahn noted that many countries do not have detailed strategies for name-based tracking of children who may have missed their vaccination schedules. He asked Omer and Lindstrand about approaches at the facility and national level for documenting and effectively tracking children who require catch-up vaccinations. Lindstrand replied that this question is pertinent for understanding how to best serve a child in administering a corrective immunization schedule after it has been delayed. To address this issue, WHO is promoting home-based records. Although digital solutions are enticing, efforts to create an electronic immunization registry that works well for everyone have so far not been successful. She suggested focusing on the basics: census data, home-based records, reporting, and a documentary instrument the public views as valuable enough to keep and bring along when receiving health services. She added that tracking COVID-19 vaccinations during the pandemic will give rise to further challenges, because these campaigns will extend beyond EPI’s typical target groups. Instead, the vaccine will likely be deployed to essential health care and social workers, older people, and people at higher risk owing to comorbidities. Lindstrand noted the lack of good instruments and procedures for reporting and follow-up; she was hopeful that the rapid development and implementation of the COVID-19 vaccine would help to fast-track the implementation of data-collection systems as well.

Accelerated Vaccination Schedules

Zahn asked about evidence related to accelerated or catch-up vaccination schedules in which multiple vaccines may be administered simultaneously. Lindstrand said it has generally been proven safe to receive multiple vaccines at the same time, including both live attenuated and other vaccines. “The human body is fantastic in being able to respond to many antigens at the same time,” she remarked. However, recommendations about the timing and spacing between different doses should be adhered to, she said. For example, if guidance about the timing of vaccine schedules (e.g., the new catch-up guidance based on WHO’s recommended vaccination schedules) is not followed, the long-term immunologic response may not be high enough to be protective.

Ensuring the Safety of the COVID-19 Vaccine

Given that COVID-19 can potentially cause long-term morbidity, Zahn asked how the safety of the vaccine can be assured—particularly with respect to longer-term potential health risks. Omer noted that the ongo-

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

ing vaccine trials are designed with large sample sizes to provide a good denominator and build confidence in moving forward with implementation. He emphasized the need to pool data from individual trials to help identify vaccine-specific adverse events as well as issues common to all vaccines for a particular pathogen. A larger body of pooled data enables better safety evaluation before the vaccination program is rolled out; it is also critical for post-marketing surveillance systems to continuously evaluate the safety of these vaccines, he added.

Omer outlined three pillars of vaccine safety reports on the use of COVID-19 vaccines. The first is the Vaccine Safety Datalink, a collaborative project between CDC and health care organizations that links databases of health maintenance organization–based networks and covers a substantial proportion of the U.S. population. Examining background rates before a vaccine is rolled out can help to identify any additional risk. He added that a separate initiative from the U.S. Food and Drug Administration, the Sentinel Initiative,13 will also likely be involved with evaluating post-marketing safety of COVID-19 vaccines as they are rolled out. The second pillar is WHO’s Global Advisory Committee on Vaccine Safety (GACVS), which is developing a set of predefined potential adverse effects for pharmacovigilance systems. In addition, GACVS is working to enhance country preparedness and help coordinate the collection of safety data worldwide. To support the third pillar—risk communication planning—GACVS has a subcommittee dedicated to risk communication activities for the vaccine, Omer added.

COVID-19 Vaccine Delivery Infrastructure

Zahn asked about international-level efforts to build the infrastructure necessary to deliver a novel vaccine worldwide in a short period of time. Lindstrand noted that the Access to COVID-19 Tools Accelerator is a global collaborative effort to accelerate the development and production of COVID-19 diagnostics, therapeutics, and vaccines, and ensure equitable access to these products.14 One of the pillars of this effort is the logistics systems for delivering vaccines. The delivery and readiness work stream within the accelerator is a joint effort among UNICEF, WHO, and Gavi, she added. Efforts are focused on helping countries prepare for likely scenarios over the next 1–2 years in terms of volumes and cold chain requirements. Lindstrand added that the majority of vaccines will go through the COVAX

___________________

13 More information about the Sentinel Initiative is available at https://www.fda.gov/safety/fdas-sentinel-initiative (accessed February 21, 2021).

14 More information about the Access to COVID-19 Tools Accelerator is available at https://www.who.int/initiatives/act-accelerator (accessed November 8, 2020).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

facility organized by Gavi,15 then shipped or distributed through UNICEF’s supply division. She noted that in high-income countries, it is possible that vaccines will be shipped directly from various pharmaceutical manufacturers. In collaboration with the Coalition for Epidemic Preparedness Innovations (CEPI),16 WHO is mapping out strategies to store and distribute potentially billions of vaccine vials. Lindstrand said there are many fronts on which CEPI and the organizations involved in COVAX are examining, adjusting, responding to, and identifying possible scenarios and trying to adopt all new evidence that emerges. Furthermore, they are working to keep WHO regional and national offices up to date. For instance, she explained how WHO plans to release a country readiness checklist for mapping out different target groups and timelines. She added that all WHO regions have also set up vaccine working groups to operationalize and adapt the global guidance according to regional need.

Omer emphasized that never before has the United States vaccinated adults in the numbers that will be needed to ensure an equitable level of protection against COVID-19 throughout communities. He suggested focusing on developing an immunization delivery plan. Remarking that “the ordinary often hampers the exceptional,” Omer noted that the bottlenecks in COVID-19 testing in the United States were not due to polymerase chain reaction technology, equipment, or primers.17 Instead, the bottlenecks were caused by lengthy turnaround times, limited availability of tests, and delays in scaling up. To implement a mass vaccination campaign in early 2021, the United States should have started preparing in March 2020, he warned, which underscores the need to set up a national adult vaccination program for COVID-19 with great speed.

___________________

15 More information about the COVAX facility is available at https://www.gavi.org/covax-facility (accessed November 8, 2020).

16 More information about the Coalition for Epidemic Preparedness Innovations is available at https://cepi.net (accessed November 8, 2020).

17 Polymerase chain reaction using specific primers is the basis of molecular diagnostic tests for detecting COVID-19 as well as other pathogens in the health care setting. More information on the science behind COVID-19 molecular tests can be found at https://discoverysedge.mayo.edu/2020/03/27/the-science-behind-the-test-for-the-covid-19-virus (accessed April 2, 2021).

Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×

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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Suggested Citation:"2 Global Vaccine Uptake During the COVID-19 Pandemic and the State of Vaccine Confidence." National Academies of Sciences, Engineering, and Medicine. 2021. The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/26134.
×
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Next: 3 Improving Access and Closing the Global Immunization Gap »
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Immunization against disease is among the most successful global health efforts of the modern era, and substantial gains in vaccination coverage rates have been achieved worldwide. However, that progress has stagnated in recent years, leaving an estimated 20 million children worldwide either undervaccinated or completely unvaccinated. The determinants of vaccination uptake are complex, mutable, and context specific. A primary driver is vaccine hesitancy - defined as a "delay in acceptance or refusal of vaccines despite availability of vaccination services". The majority of vaccine-hesitant people fall somewhere on a spectrum from vaccine acceptance to vaccine denial. Vaccine uptake is also hampered by socioeconomic or structural barriers to access.

On August 17-20, 2020, the Forum on Microbial Threats at the National Academies of Sciences, Engineering, and Medicine held a 4-day virtual workshop titled The Critical Public Health Value of Vaccines: Tackling Issues of Access and Hesitancy. The workshop focused on two main areas (vaccine access and vaccine confidence) and gave particular consideration to health systems, research opportunities, communication strategies, and policies that could be considered to address access, perception, attitudes, and behaviors toward vaccination. This publication summarizes the presentations and discussion of the workshop.

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