Can you get sick with *both* COVID-19 and the flu at the same time?

Yes, it is possible to have co-infection with COVID-19 and influenza and thus experts are concerned about the potential for a “twindemic” this winter. When the pandemic began, it was initially thought that co-infections with SARS-CoV-2 and other respiratory pathogens were rare, but as case numbers increased, it became clear that it is possible. Generally speaking, anytime that you have one infection (whether viral or bacterial), your immune system can be slightly weakened and make you more susceptible to other diseases. Other than the difficult task of determining what infection someone might have and thus deciding on necessary treatments and isolation/quarantine recommendations, the concern is that having both infections could be more dangerous than having one alone. 

There are small and/or preliminary studies showing that patients with co-infection will fare worse. While we are early in the flu season, there is one known case in California already this year (the patient lives in Solano County and is under 65). Flu activity in the US remains low so far, but that is typical for this time of year- in California, we typically see flu activity pick up in December and peak around late January or February. Unfortunately COVID-19 numbers are rising quickly as we head into winter as the rates of illness and hospitalization increase across the country. In fact, of the 10 million cases in the US that have been diagnosed since March, 1 million of them occurred in the last month. 

One piece of good news is that if you get your flu shot, not only are you protecting yourself from the flu, there is some evidence that it also decreases your risk of having a severe case of COVID-19 that requires hospitalization. A study recently published in the Journal of American Board of Family Medicine found that people who had been vaccinated last season against flu were more than two times less likely to be hospitalized for COVID-19 and more than three times less likely to be admitted to an ICU. 

So, bottom line (no surprises here)… go get your flu shot if you haven’t yet, wear a mask when appropriate and wash your hands regularly. It’s believed that COVID-19 precautions contributed to keeping the flu season in the Southern Hemisphere quite mild,  so let’s hope we can say the same for our flu season when we look back next spring.

Jackie Phillips, MD, November 10, 2020