Should I wait to get vaccinated so that my immunity lasts through the end of the season?

 No. CDC recommends that influenza vaccination begin as soon as flu vaccine becomes available and continues throughout the flu season. The flu season is unpredictable, and since it takes about two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection, it is best that people get vaccinated early so they are protected before influenza begins spreading in their community. While immunity can vary by person, previously published studies suggest that immunity lasts through a full flu season. Although adults 65 and older typically have a reduced immune response to flu vaccination compared with young healthy adults, their immune protection still extends through one flu season. In addition, a review of published studies concluded that no clear evidence exists that immunity declines more rapidly in the elderly. Note: The high-dose vaccine for people aged 65 and older is intended to create a stronger immune response in this age group.