The most effective way of preventing the flu is with an influenza vaccination. Every fall you should be immunized against strains that have developed since the previous outbreak. If you are vaccinated against one or more strains, you may still come down with flu, but symptoms are likely to be milder than they would have been had you not had an influenza vaccination.
Influenza vaccine is available through physicians and public-health facilities and many companies provide flu vaccines on-site for their workers. Because influenza is a serious threat, the CDC recommends vaccination for everyone 6 months of age and older and others at high risk of flu complications:
If you have HIV (human immunodeficiency virus) or AIDS (acquired immunodeficiency syndrome), you should take special precautions against other infections, such as the flu. That's because you have a disease that makes it difficult for your immune system to fight them. Vaccines (i mmunizations) can help your body defend itself against infections. However, if you have HIV/AIDS immunizations may effect you differently than people who don't have HIV/AIDS.
Not all vaccines are safe for people with HIV/AIDS...
Adults 65 and older
Those with chronic medical conditions, such as diabetes and asthma
People with a weakened immune system, like those with HIV/AIDS
The seasonal flu vaccine is available in two forms. One is the injectable vaccine made from an inactivated virus. This form is usually given as a single injection and is approved for people 6 months of age or older. The other form is given as a nasal spray called FluMist. This form of the vaccine is a live and weakened form of the flu and is approved for all healthy people 2-49 years of age who are not pregnant. If you are pregnant you can only receive the injectable form. The CDC now recommends the nasal spray vaccine for healthy children 2 through 8 years old when it is available. Both vaccines are given as a single dose, although children who are receiving vaccination for the first time receive two. Some people develop low fever and muscle aches as side effects of the vaccine.
Intradermal shots use smaller needles that only go into the top layer of the skin instead of the muscle. They're available for those aged 18 to 64.
Egg-free vaccines are now available for those aged 18 to 49 who have severe egg allergies.
High-dose vaccines are meant for those age 65 and older, when available, and may better protect this group from the flu.