Once you receive your flu shot, it takes approximately 10 to 14 days for your body to build up adequate immunity. If you have been exposed to the flu within a few days prior to receiving the shot, you may still become infected with the flu. The shot does not cause the flu. Immunity peaks at approximately two months after receiving the shot. The vaccination is effective for the current flu season.
Flu viruses change every year, so it is advisable to receive a new vaccination each year.
Influenza does not usually reach Michigan until January and peaks around February or March. Influenza vaccine generally causes only mild side effects that occur infrequently. Any side effect would occur within 6-12 hours after vaccination and can persist for one to two days. These reactions consist of soreness at the injection site, fever, chills, headaches or muscle aches. The flu shots are administered by a Visiting Nurse Association nurse.