The influenza vaccine is given to protect against influenza in children older than six months of age and adults. The World Health Organization monitors influenza illness throughout the year and make recommendations on which three influenza types are likely to cause the most illness in the northern and in the southern hemisphere during their respective influenza seasons. Vaccine ingredients are specific to the brand of influenza vaccine they are associated with and may vary to year. Specific information on ingredients in the vaccines use each season can be found on the individual vaccine datasheets.
Influenza types in the vaccine usually change season to season
Last updated: 04-11-2013