get those vaccinations

You still need a flu shot even if you’ve already been ill

Q: I was recently sick and I think it must have been the flu. Do I still need a flu shot?

A: The short answer is yes, get vaccinated. You are among the millions who have already suffered a respiratory illness this season. We are experiencing a “tripledemic” with flu, COVID-19 and respiratory syncytial virus (RSV), causing a large number of infections and hospitalizations. RSV and about a dozen other common viruses cause flu-like illnesses in adults.

That being said, we cannot be sure that you had the flu without a test. Before we had easily available viral testing at doctors’ offices, we frequently blamed the flu for most of our wintertime coughs and colds. We now know that flu does not account for the majority of these flu-like illnesses. All those rules, like you know it is the flu when you have a fever, cough, and muscle aches, have turned out to be untrue. Home testing may soon come to the rescue, though. COVID-19 home testing has been a game changer allowing people to self-isolate and seek treatment sooner. In the not-too-distant future, we will have home tests to detect other common infections, including the flu. Home testing will help people better decide when to seek medical care.

If you did have the flu, the recommendation is still to get vaccinated. Flu vaccines cover two A strains and two B strains. Despite having an illness from one strain, you are still at risk for the other three. Commonly, A strains predominate at the beginning of the season and B strains lead late in the season. Currently, type A (in particular, H3N2) is the predominant strain causing infections.

Flu vaccine effectiveness in preventing infection ranges from 16 to 75 percent, depending on how well the vaccine matches the circulating strains as well as the person’s health and age. Like COVID-19 vaccines, flu vaccines are better at preventing severe illness than infection. Flu shots reduce the risk of being hospitalized, particularly for those at the highest risk. People aged 65 and older make up ninety percent of those hospitalized with the flu. The vaccines also prevent heart attacks, which are six times higher during and then following a flu illness. People with other medical conditions, such as lung and heart disease, also do much better when vaccinated.

Another benefit is that vaccination cuts the spread of the flu. A person with the flu gives it to one or two additional people on average. Having more people vaccinated for the flu helps reduce the spread to vulnerable populations, such as infants, the elderly and those with medical problems. Unfortunately, less than half of Americans get vaccinated yearly.

Although flu season started early this year, there is nothing indicating it will end early. Flu activity typically peaks in February. You should get vaccinated without delay.

Megan Berman
Richard Rupp
Vaccine Smarts is written by Sealy Institute for Vaccine Sciences faculty members Drs. Megan Berman, an associate professor of internal medicine, and Richard Rupp, a professor of pediatrics at the University of Texas Medical Branch. For questions about vaccines, email