why do we get a flu shot every year

Everyone can benefit from the flu vaccine, but itвs crucial
for people in certain groups. Getting the flu puts you at risk of secondary infections and serious complications, especially if youвre in a high-risk group. Possible complications include: The very young are at an increased risk of complications from the flu, and itвs important for them to stay up to date on their flu vaccinations. Itвs also important to make the flu vaccine a priority if you: have a chronic health condition, such as diabetes, asthma, or heart disease Pregnant women should get vaccinated, no matter what their stage of pregnancy.

If youвre pregnant, changes in your heart, lungs, and immune system make the symptoms of the flu more dangerous for you and your developing fetus. Among other dangers, getting the flu raises your risk of premature labor and delivery. Getting the flu shot will help protect you and your unborn baby, even after birth.

If youвre concerned about thimerosal, a mercury-based preservative used in flu vaccines, you can request a preservative-free vaccine. If youвre breast-feeding, you should also get a flu vaccine to protect yourself and pass on protective antibodies to your baby. This will lower your babyвs risk of getting the flu. Once your baby is 6 months old, they can safely get the vaccine themselves. What you call influenza isn't a specific virus which is always the same, but a virus that has numerous different strains.

Flu virus is constantly alive on this planet, and there are numerous different types, such as the ones which infect humans, the ones that infect birds, and occasionally a virus that mutates to infect humans although it shouldn't as it infects birds only. Viruses evolve very quickly. The strain of flu virus which was rampant last year definitely won't be the one to look out for this year.

What scientists are doing is a very difficult job - they're tracking the progress of different flu virus strains and trying to make an educated guess about the strain or strains which might spread the most during the flu season. And then they come up with a flu vaccine which is a mix that targets the several strains that were identified as being the biggest threat. It's a hit or miss kind of thing, and it's quite possible that the scientists get it wrong, or not necessarily wrong, but something happens in the virus evolution process that renders this year's vaccine useless.

Also, it's possible to get a flu vaccine and still get flu - if you happen to come in contact with a strain that wasn't targeted by the vaccine. Viruses evolve very very quickly, so vaccine isn't failsafe, virus can evolve in some other person, you come in contact with the virus and get infected despite being vaccined against the original strain.