September 24, 2020

Questions, answers on flu season and COVID

Infectious diseases specialist Thomas Talbot, MD, MPH, chief hospital epidemiologist at Vanderbilt University Medical Center, answers questions about the rapidly approaching U.S. flu season and how it might play into the COVID-19 pandemic.


by Paul Govern

Infectious diseases specialist Thomas Talbot, MD, MPH, is professor of Medicine and chief hospital epidemiologist at Vanderbilt University Medical Center. He spoke about the rapidly approaching U.S. flu season and how it might play into the COVID-19 pandemic.

Thomas Talbot, MD, MPH, answers questions about upcoming flu season and COVID-19.
Thomas Talbot, MD, MPH


Q: When should people get their flu shot?

A: Folks should start getting them now. Before mid-October and definitely no later than Halloween.


Q: Once flu season starts, if you develop flu-like symptoms, should you get tested for COVID?

A: I think definitely for a patient being admitted to the hospital, if you’re a clinician who’s considering flu, you’ve got to consider COVID and vice versa. Part of what we are working on is how you evaluate patients that come into the clinic with these symptoms. I think it’ll be based on the exact symptoms the patient presents with and what kind of flu activity we’re seeing at the time.

By November, when flu has started to pick up, when you come into the clinic with a new cough you may be more likely to be tested for both.

Another possibility could be that we’ll test you for COVID and if you’re negative, we’re going to presume flu and act as such. If we had enough testing and resources, potentially we would test everybody with flu-like illness for both diseases, but we’re concerned we won’t have that kind of capacity.


Q: What about otherwise healthy people who are prone not to see a clinician for flu? If they develop what appear to be classic flu symptoms, given the COVID pandemic, should they seek clinical evaluation?

A: Yes, I think you should have a lower threshold to be evaluated, especially if COVID is a possibility, because of all the ramifications with that diagnosis. I think people already have a lower threshold to get evaluated than they would pre-COVID and that will continue on to flu season, for sure.


Q: Is the social distancing wrought by COVID-19 expected to affect flu incidence?

A: We have some reassuring signs that if we follow the precautions we’re using for COVID, like masking, distancing and avoiding large gatherings, this will impact other respiratory viruses, flu included.

Some data came out in the last few weeks from Australia, where their flu season has just ended and where they had widespread implementation of masking, distancing, gathering restrictions and other interventions. They had a very mild flu season with a very marked reduction in cases. That could be what we see, but for that to happen we don’t want to lay off the gas too early on interventions like masking.


Q: Given the numbers of COVID-19 inpatients we’re treating at VUMC, would a typical flu season, with typical rates of serious complications such as pneumonia, threaten to strain our inpatient resources? (As of Sept. 23, the COVID-19 inpatient census across Vanderbilt Health hospitals was 28.)

A: That’s why I think you’re hearing more messaging this year about getting a flu vaccination, so we can nip those complications and hospitalizations very early.

We learned in the spring that when people avoided health care there were a lot of unintended health consequences, so we’ve really committed not only to handle COVID illness but also make sure patients can receive the full complement of health care at our facilities. That means our hospital is full, and if you layer on a flu season with that, it could strain our capacity.


Q: If you get the flu in the face of the COVID pandemic, could you somehow be at risk for a worse outcome?

A: I haven’t noted any evidence of increased risk of COVID if you get flu, or vice versa. We do have some data from early in the pandemic of co-infection with both COVID and flu. You can imagine that could result in a more severe illness — one is bad enough; both at once could be worse.

One thing we’re seeing with COVID is patients are noticing lingering health effects, some of which are pulmonary. So, for those who haven’t fully recovered from COVID, you can imagine how throwing in a case of influenza could knock you down for a while.


Q: What is the typical annual U.S. flu vaccination rate and why don’t more people get vaccinated?

A: If you look at health care workers, we’ve done better with that as a population. In part because it’s now reported and required in a lot of places. Health care workers are getting flu vaccine at rates in the neighborhood of 85%, and in the case of acute care hospitals, greater than 90%. In the general public, it’s not there, and it differs by group.

Older adults are reaching higher vaccination rates and so are children. For young adults the rates are much lower, around 30% to 40%. In part, that’s because those individuals may not perceive themselves at risk of getting sick with flu, and they may not totally appreciate their role of spreading it to other people.

The otherwise healthy adult who’s mildly symptomatic with flu may think he has “just a cold” and feel like, “Oh, that’s not flu, with flu you’re laid out in bed. I’m sure I’m fine.” That actually may be how some adults present with flu, but they’re nonetheless very much at risk of spreading the infection to other people. It’s particularly important for those who might be in contact with those at higher risk for influenza illness and complications to get vaccinated to protect those contacts.


VUMC employees can find more information about vaccination at the Vanderbilt Faculty and Staff Health and Wellness website.