The near-lack of a flu season during last winter’s COVID-19 surge may mean a 2021-22 influenza season that is more severe than average —and hit young children particularly hard — because of waning population-level immunity, according to research from Pitt’s Graduate School of Public Health.
The two studies by Pitt Public Health scientists suggest that increased flu-related hospitalizations and deaths can be mitigated if vaccination rates are between 20 and 50 percent higher than those in recent flu seasons.
“The ‘twindemic’ — a coinciding flu and COVID-19 epidemic — overwhelming our hospitals was thankfully avoided last year. But that does not mean it is no longer possible,” said Mark Roberts, director of the Public Health Dynamics Laboratory at Pitt Public Health and senior author on both studies. “If anything, our models show that we should be more concerned this year about the possibility of a surge in COVID-19 hitting at the same time as a massive flu outbreak in areas of the country with low vaccination rates against both diseases.”
Pitt will hold flu shot clinics on the Oakland campus for faculty, staff and students over the next six weeks.
9 a.m. to 4 p.m. Sept. 15, Petersen Events Center
6:30 a.m. to 1:30 p.m. Sept. 21, Petersen Events Center
10 a.m. to 2 p.m. Sept. 29, William Pitt Union (at the HealthyU Fair)
10 a.m. to 2 p.m. Sept. 30, Bridgeside Point
10 a.m. to 2 p.m. Oct. 4, Biomedical Science Tower South, Room 123
10 a.m. to 2 p.m. Oct. 12 and 14, William Pitt Union, Assembly Room
The Bradford campus will hold flu shot clinics from 10 a.m. to 2 p.m. Oct. 12 and 20 in the Frame-Westerberg Commons, Mukaiyama University Room. Pitt–Johnstown will hold a clinic from 10 a.m. to 3 p.m. Sept. 22 in the Student Union’s Cambria Room.
No clinics will be held at Greensburg or Titusville. Pitt employees with UPMC Health Plan coverage and their families can receive a flu shot at no cost, as well as receive Wellness Incentive credit, at local pharmacies by just showing their UPMC insurance card.
Falk Pharmacy in Oakland also is giving free flu shots from 9 a.m. to 4 p.m. Tuesdays through Thursdays. You can schedule a flu shot appointment online or by calling 412-623-6222 (option 0). Walk-ins also welcome.
Studies’ authors say vaccines essential
The Pitt Public Health scientists published the findings of both studies in medRxiv, a preprint website, and announced their results Aug. 30, ahead of peer-reviewed publication in order to get the word out about the possible health crisis.
“As COVID-19 containment measures — such as masking, distancing and school closures — are relaxed around the world, we’re seeing a fierce resurgence of other respiratory viruses, which does not bode well for the coming flu season,” Roberts said. “In a worst-case situation with a highly transmissible flu strain dominating and low influenza vaccination uptake, our predictive models indicate the potential for up to nearly half a million more flu hospitalizations this winter, compared to a normal flu season. Vaccinating as many people against flu as possible will be key to avoiding this scenario.”
Roberts and his colleagues performed two independent analyses, using different mathematical modeling platforms and publishing the results separately. Both models produced consistent, complementary results.
Pitt Public Health postdoctoral associate Kyueun Lee led a team that found the coming influenza season will likely bring about 600,000 hospitalizations, at least 100,000 more than would happen in a normal season. In a worst-case scenario where vaccine uptake is low, there would be more than 400,000 additional hospitalizations. Getting 75 percent of Americans vaccinated against flu, rather than the typical 50 percent, would be needed to avoid the additional hospitalizations, according to the model.
Lee also went a step further and examined what would happen in future years if COVID-19 precautions persist and this flu season also is blunted. As would be expected, natural immunity against flu continues to plummet, further increasing the odds of an ever-larger flu outbreak with high hospitalization rates whenever social activity returns to normal.
“This is not to suggest that we should stop COVID-19 mitigation efforts to avoid a severe future flu season,” Roberts said. “Instead, it shows that more of us — particularly young children — will be susceptible to the flu and that vaccination is absolutely essential to avoiding bad outcomes.”
Additional authors on one or both of these studies are David D. Galloway, Jonathan M. Raviotta, Richard K. Zimmerman, Hawre Jalal, and Donald Burke, all of Pitt.
— Susan Jones
Have a story idea or news to share? Share it with the University Times.