Columbia subject headings:
Antiviral agents.
Influenza--Prevention.
Harvard subject headings:
Antiviral agents--Effectiveness.
Antiviral agents.
Epidemics--Prevention.
Influenza--Prevention
Influenza--United States--Epidemiology.
Influenza--Vaccination--United States.
Princeton subject headings:
Antiviral agents--Effectiveness.
Antiviral agents.
Epidemics--Prevention.
Influenza--Prevention.
Influenza--United States--Epidemiology.
Influenza--Vaccination--United States.