Flu Shot Facts

  It is that time of year again for flu shots. Here are a few interesting facts you may not be aware of. The shots are generally free or cheap at Walmart and various pharmacies. T

The flu virus comes in numerous strains, or types. The strain called H1N1 is now a common type of seasonal flu. The bird flu, also known as H5N1 or H7N9, has made a lot of birds sick, but rarely spreads to humans unless they have handled infected birds.

Each shot contains a tiny bit of dead flu virus. The virus is grown in fertilized chicken eggs, then extracted and deactivated with microscopic amounts of formaldehyde. A chemical called octylphenol ethoxylate pulls out even smaller pieces of virus, which helps reduce the chances of side effects. Gelatin holds the virus together and keeps it stable during shipping, and a preservative called thimerosol keeps the vaccine from going bad on the shelf.

There is no reason to be concerned about any of these chemicals; they are present in such small quantities that your body will barely register them.

You should get a flu shot even if you think you never get the flu. Just because you have never had it before does not mean you are invincible. In addition, even if you never have symptoms, you could be carrying the virus around, exposing everyone else to it.

You need to get a flu shot every year. There are many types of flu. Each year, researchers and public health officials determine which strains seem like they are going to be a threat, and formulate a vaccine that protects against those strains. To stay protected against the latest flu risks, you must keep your shots up to date.

This year's flu shots will protect against three or four strains. According to the Centers for Disease Control and Prevention, three or four kinds of flu viruses commonly circulate among people today: influenza A (H1N1) viruses, influenza A (H3N2) viruses, and influenza B viruses. The 2020-2021 flu shot has been updated to protect against three virus strains: A/Guangdong-Maonan/SWL1536/2019 (H1N1) pdm09-like virus, A/Hong Kong/2671/2019 (H3N2)-like virus, and B/Washington/02/2019 (B/Victoria lineage)-like virus.

Quadrivalent flu shots, which are designed to protect against four types of flu, will protect against an additional B virus called B/Phuket/3073/2013-like (Yamagata lineage) virus.

The flu shot can't give you the flu. The flu shot is either made with dead (deactivated) flu virus or, in the case of the recombinant flu vaccine, with no actual virus at all. You may have some side effects after getting your shot, but those are usually limited to pain or swelling around the site of the injection. In rare cases, you may have a low-grade fever or mild muscle aches, but these are side effects, and not the flu.

You can get the flu shot if you are allergic to eggs. For a while, doctors were cautioning people with egg allergies to stay away from the flu vaccine, but this seems to have been unnecessary. The American Academy of Allergy, Asthma, and Immunology recently stated that “no special precautions are required for the administration of influenza vaccine to egg-allergic patients, no matter how severe the egg allergy.” If you are concerned about an allergic reaction, talk to your doctor. He or she may be able to get you an egg-free flu shot.

Incidentally, If you get the flu, antibiotics will not help. The flu is caused by a virus, not bacteria; antibiotics respond only to bacteria. Antibiotics will not do anything to fight the flu virus.