No, really, get a flu shot: Frequently asked questions about the flu vaccine

Fall is flu shot season

October marks the start of cold and flu season in the United States. While research shows getting the flu vaccine can reduce influenza illnesses by 40 to 60%, recent studies suggest a significant portion of adults still do not intend to get a flu shot.

We asked Allison Bartlett, MD, an expert in infectious diseases at the University of Chicago Medicine, a few common questions about the flu vaccine to help assuage any doubt that the flu shot is well worth the needle prick.

Why do I need a flu vaccine every year?
We have to get the vaccine every year for a few reasons. Unfortunately, we don’t yet have a universal flu vaccine that would protect us from all influenza for all time. Scientists are working on one, but until then, we have to get a vaccine every year. Secondly, the flu virus is constantly changing, so the flu strains in the vaccine are updated every year by the World Health Organization to ensure it includes inactive strains of the viruses that are predicted to circulate. Lastly, the effectiveness of the current vaccines wears off over time, so if you get your flu shot in July or August, the immunity might wear off by the height of flu season in January and is very likely to wear off by next flu season.

When should I get a flu shot?
It’s important to get the vaccine to prevent the flu. So in the early fall, before the virus starts circulating in the community, would be the ideal time to get the shot. It takes about two weeks to be fully protected after vaccination.

Will the shot inject me with the actual flu?
No, the vaccine is made of an inactive version of the flu and, therefore, is not infectious. The nasal spray is made of a weakened form of the virus and cannot cause influenza, but may cause a mild runny nose for a day or two.

Can people with egg allergies still get a flu shot?
Yes! It’s safe for people with egg allergies to get a flu vaccination, including vaccines made in eggs; however, those with a severe egg allergy are encouraged to get the vaccine in a medical setting with supervision by a health care provider who can manage an allergic reaction should one occur.

What about the non-needle versions of the vaccine?
While the nasal vaccine was taken off the market for a few years because it was less effective, it has been reformulated and is now back and available.

Is there a specific shot for seniors?
It is recommended that people 65 years and older get the flu shot and not the nasal spray vaccine. At UChicago Medicine, we give seniors the quadrivalent flu shot, which includes inactive versions of all four strains that are predicted to circulate, to make sure those 65 years old and older are well protected.

Who shouldn’t get a flu shot?
Children younger than six months old should not get a flu shot, nor should people with severe, life-threatening allergies to flu vaccines. Those who are immunocompromised should talk with their health care provider before getting the vaccine as well as those who are not feeling well. To protect individuals who cannot get the flu shot, it is vitally important that everyone around them get their flu shots.

Allison Bartlett, MD

Allison Bartlett, MD, MS

Allison Bartlett, MD, MS, specializes in the medical management of acute and chronic infectious diseases. She also is working to improve the safety and efficacy of antibiotic use in children.

Learn more about Dr. Bartlett.