Flu and Seasonal Influenza Vaccine
[Section 1.1] Flu and seasonal vaccines are reformulated annually because the influenza viruses change in ways that make a previous year’s vaccine ineffective. Included are standardized amounts of the Hemaglutin (HA) protein from representative seed strains of the two human influenza A subtypes (H3N2 and H1N1) and one of the two influenza B lineages. Read more