Public Health

Vaccination strategies for infectious diseases:

1) Seasonal influenza vaccine and surveillance

Each year, there are new recommendations on which influenza viruses should be included in the influenza vaccine.  How does surveillance of the circulating influenza viruses lead to development of the vaccine?  Why are some years more or less effective at preventing seasonal influenza?

APA Style with minimum of 450 words, with quotation, anotations and 3 references.