influenza a – whats hot tarrant symposium 2012 kevin fonseca clinical virologist provlab...
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Influenza A – What’s Hot
TARRANT Symposium 2012
Kevin Fonseca
Clinical Virologist
ProvLab
Kevin.fonseca@albertahealthservices.ca
Theme
Recent Controversies in Influenza Research
Animal Models Lively Discussion
Holy Grail of “Influenzaologists”
The Perfect Vaccine Able to predict Pandemics to the day/hour Able to clinically diagnose with 100%
certainty The Perfect Influenza test in 10 secs The Perfect Model
Controversy Balance the right to research with perceived
ethical obligations Create a potential bio-weapon Provide data to “terrorist organisations” Risks of pathogen escape (small-pox, anthrax,
influenza) Safety of the public What about “military research” When is research just to dangerous to conduct Does understanding the biology of infection in
animal models really help ?
Mortality = 58%
Belser et al Disease Models & Mechanisms 2011
Pandemic vs Seasonal H1N1 (Pre-pandemic)
Virus Ferrets Humans
Pandemic
Mild
Severe
Fatal
30% sneezed
No deaths
Found in GI (70%)
Generally mild
Not associated with GI symptoms
Lots of person-to-person transmission
Spectrum of illness with some fatalities
Some countries reported higher incidences or morbidity & mortality
50% sneezed
50% died
Found in GI (20%) [& contacts]
10% sneezed
No deaths
Found in GI (10%)
Seasonal 100% sneezed
No deaths
No GI infection
Generally mild
No GI symptoms
Fatalities occurred
Q – How accurate was the ferret model in predicting human disease ?
Reality ?
Ferret Model A(H3N2)v is easily
transmissible Causes mild illness
Human Cell Model A(H3N2)v > H3N2 Reaches a higher
titre
Observed Handful of cases (12) Mainly in young
children Mild illness Few hospitalizations Low level of
transmission thus far ? Pandemic
potential? Not covered by the
vaccine
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