Q. Does CDC recommend influenza vaccination (flu shot) to reduce the likelihood of getting a respiratory tract illness that could be mistaken for SARS?
No. CDC does not recommend that influenza vaccination be considered as a way to avoid confusing influenza disease with an influenza-like illness caused by SARS. Influenza vaccination is the primary means of preventing influenza and its severe complications, including pneumonia, hospitalization, and death.
Complications from influenza infection most often occur among persons > 65 years of age, persons < 65 years of age who have certain medical conditions, and children < 2 years. Influenza vaccination is targeted toward these high-risk groups, all persons 50-64 years (because a high proportion of them have at least one high-risk condition), health care workers, and household contacts of high-risk persons. Influenza viruses are only one cause of influenza-like illness (fever, body aches, headaches).
Even during the fall and winter influenza season, many other infectious agents (including SARS-associated coronavirus) can cause influenza-like illness, and most influenza-like illnesses are not caused by influenza viruses (or SARS-associated coronavirus). The influenza vaccine can prevent 70-90% of influenza-like illnesses caused by influenza viruses, but does not prevent influenza-like illness caused by infectious agents other than influenza viruses.
Q. When should I get a flu shot ?
Beginning each September, flu shots should be offered to persons at high risk when they are seen by health-care providers for routine care or as a result of hospitalization. The best time to get a flu shot, if you are in a high-risk group, is from October through November.
You should avoid getting a flu shot too early, because protection from flu can begin to decline within a few months after getting the shot. Flu activity in the United States generally peaks between late December and early March. You can still benefit from getting a flu shot after November, even if flu is present in your community. Vaccine should continue to be offered to unvaccinated persons throughout the flu season as long as vaccine is still available. Once you get a flu shot, your body makes protective antibodies in about two weeks.
The annual supply of inactivated influenza vaccine and the timing of its distribution cannot be guaranteed in any year. Information regarding the supply of 2003--04 vaccine might not be available until late summer or early fall 2003. To allow vaccine providers to plan for the upcoming vaccination season, taking into account the yearly possibility of vaccine delays or shortages and the need to ensure vaccination of persons at high risk and their contacts, the ACIP recommends that vaccine campaigns conducted in October should focus their efforts primarily on persons at increased risk for influenza complications and their contacts, including health-care workers.
Campaigns conducted in November and later should continue to vaccinate persons at high risk and their contacts, but also vaccinate other persons who wish to decrease their risk for influenza infection. Vaccination efforts for all groups should continue into December and beyond.