I got a flu shot back in sept, but it doesn't seem to be effective. Is it ok to go get a 2nd shot in feb?

How do you know that it isn't effective? It is important to understand how the vaccine works.

The flu shot does not protect against all flu. It contains 3 strains of influenza virus that are chosen by experts every year as most likely to cause a flu outbreak. These strains are chosen >6 months in advance. It is important to understand that there are literally thousands of known strains of influenza virus, and infection by any one can cause the flu.

No vaccine is perfect. Even if it contained the correct strains, your body may not have mounted a strong enough response to the vaccine in October to fight off the infection in January. Estimates of vaccine effectiveness generally range between 50-80%.

If you've been getting sick recently, it's likely that you did not have the flu. Most people mistake symptoms of the common cold for the flu. Colds are usually caused by different viruses than the influenza virus. These include coronavirus, rhinovirus, adenovirus, etc. While similar to a cold, the flu often causes severe muscle aches, headaches, and high fevers.

why do you think it wasnt effective? Do you have the flu?

What do you mean it doesn't seem to be affective? Did you have the flu? If so, then you don't need a flu shot again. You had the flu. If you haven't had the flu, I guess its working. Don't ever get a second shot.

No. It is not okay. It will probably make you sick as a dog. The shot prevents the most prevalent form of the viral influenza. You have probably been coming down with miscellaneous colds and other bugs.

If you get a second shot for the same strain of the influenza virus, your immune system will kick in to fight the second shot. And VOILA! You will have ugly flu-like symptoms.

Go see your doctor if you are feeling poorly. If it is the bacterial form of the flu, it can be treated.

A flu shot does not deter every cold that is out there, only certain strands. It takes 2 weeks for a flu shot to come into effect. You can still get a cold. Becareful that you wash your hands after touching a door knob, a dirty table, things that children have had. A flu shot in February is meaningless. September and October is perfect time for the shot. Even December is not too late. By February, the flu season is almost over. The flu shot is suppose to last for a year.