HLTB21H3 Lecture Notes - Antigenic Drift, 1918 Flu Pandemic, Influenza Vaccine
Document Summary
Seasonal influenza: rates increase in colder seasons due to more people indoors, u. s. between 1976-2006 flu-associated deaths range from. 3,000 to 49,000 per year: 90% of deaths occur in those aged >65 yrs (risk group) Epidemic/pandemic influenza: surges in influenza cases/deaths caused by a highly virulent and infectious strain. Can show diff peeks: can be differences in risk groups and/or seasonality. Limited lasting immunity for influenza: measles- life long once contracted and need large population density, influenza- no immunity, small population. First evidence in 1400s and 1500s: none in new world due to no domestic animals. 1781 pandemic: 2/3 of rome and of britain infected, north america, west indies and south america. Spanish flu: came from end of wwi, huge censorship in spain, publicize more. ~500 million infected (1/3 of global population) ~50 million global deaths: more death than wwii, from france to us in 17 days, 1-72thousands infected.
