John R. La Montagne Memorial Symposium on Pandemic Influenza Research Meeting Proceedings (2005) / Chapter Skim
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6 Plenary Speakers, Day 2
6 Plenary Speakers, Day 2
Pages 103-132
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From page 103... ...
How can we best use antivirals to reduce mortality and morbidity, protect key personnel, reduce social disruption given significant mortality, and reduce disease attack rates while we prepare a vaccine? More difficult to model than the impact of antivirals is the role of measures to increase "social distance" -- such as closing schools or limiting travel within a country -- in slowing the spread of disease or reducing attack rates.
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From page 104... ...
One output of the simulation model we have constructed is maps of population density, which use colour to represent reas of the modeled region in which infection is present or trestment being undertaken.. Capturing age and household structure are also critical for realistically modeling influenza transmission, and the model incorporates data we have collected for Thailand.
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From page 105... ...
That means that should a pandemic strain of H5 emerge through reassortment, its virulence will be less than what we are now seeing. However, if the current human virulence of the avian H5N1 virus remained unchanged for an emergent pandemic H5 strain, severe clinical disease would actually occur in a much higher proportion of cases.
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From page 106... ...
The model can incorporate delays, detection thresholds, and limits on drug use, as well as the impact of measures to increase social distance. Currently I am less satisfied with our estimates of the latter, so I will not present results here.
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From page 107... ...
Within a week of the arrival of the index case of SARS at the Metropole Hotel in Hong Kong, the disease had spread to multiple countries around the world.
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From page 108... ...
The Landscan datset map showing areas of high population density offers some insight into this. Besides quantifying the international spread of influenza, the MIDAS initiative and various projects funded by the European Union are modeling pandemic preparedness options within the continental United States and Europe.
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From page 109... ...
PLENARY SPEAKERS DAY 2 109 (Slides not available)
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From page 110... ...
We have looked at recombinant baculovirus-expressed HAs, and a variety of studies are looking at both whole virus and split virus for H2N2 and H9N2. Some of the first data came from Karl Nicholson and his group in England, who looked at egg-grown Duck Singapore as a potential vaccine for H5 influenza when the first outbreak was noted in Hong Kong in 1997.
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From page 111... ...
Investigators looked instead at the radial hemolysis test. The vaccine did have a tendency -- when adjuvanted with MF59 -- to induce antibody with much greater ability to recognize the Duck Singapore virus than the Human Hong Kong virus, which would be the target of the vaccine program.
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From page 112... ...
The expressed hemagglutinin looked like a promising approach, but that is not a validated strategy for influenza control. Pandemic planning should thus confirm whether this approach is actually effective in preventing conventional influenza.
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From page 113... ...
The first product is from Sanofi-Avantis and second is from Chiron. Both manufacturers used a production facility to produce subunit vaccines that are very similar in principle to the vaccines that these manufacturers are licensed to produce for conventional influenza.
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From page 114... ...
We should also look at the schedule and route of administration, including not only inactivated vaccine but also intranasal, transcutaneous, and intradermal administration, again trying to reduce the dose. We have looked a bit at intradermal vaccines for conventional influenza vaccines, using a clever device made by Becton Dickinson that nurses were able to use very effectively to deliver vaccine intradermally.
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From page 115... ...
It would be useful to use the live vaccines to develop a form of human challenge model for pandemic influenza, similar to the models that have been so useful for conventional influenza. This type of model would be especially important as we try to get an early signal as to whether candidate vaccines would in fact protect against protection and shedding.
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From page 116... ...
116 PANDEMIC INFLUENZA RESEARCH We need to take that step as soon as possible, potentially using the human challenge model as an early indicator of whether these vaccines have promise.
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From page 117... ...
PLENARY SPEAKERS DAY 2 117 Plenary Presentation Slides-Dr. John Treanor
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From page 123... ...
PLENARY SPEAKERS DAY 2 123 (Slides available on accompanying CD)
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From page 124... ...
After SARS and the laboratory infection of humans, the advice given to countries that lack adequate infrastructure is: do not attempt to isolate viruses. In other words, Hong Kong should not have been isolating H5N1 viruses in 1997 but instead should have been using molecular techniques and reverse transcription- polymerase chain reaction, or sending samples to experts around the world.
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From page 125... ...
However, they can reduce viral load below the level of transmission. In Hong Kong, agricultural researchers have clearly shown that the vaccines now available reduce the load so that transmission does not occur.
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From page 126... ...
In November 2002 the virus acquired the ability to kill waterfowl in Hong Kong. All the waterfowl in Kowloon Park in central Hong Kong, including flamingoes and other decorative birds, were susceptible and died of neurological infection.
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From page 127... ...
The immediate issue is to reduce the likelihood of human-to-human transmission by reducing the viral load in poultry. And we can do that: the international agencies must come aboard to reduce the ducks in live markets and standardize agricultural vaccines.
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From page 128... ...
128 PANDEMIC INFLUENZA RESEARCH Plenary Presentation Slides-Dr. Webster
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From page 131... ...
PLENARY SPEAKERS DAY 2 131 (Slides available on accompanying CD)
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