Last year, as COVID-19 cases surged to record highs in mid-Michigan and across the country, seasonal flu infections were much lower than normal.
Scientists had worried about the possibility of a concurrent flu outbreak, creating what some feared would be a “twindemic.” Ultimately, however, the recorded number of patients with flu-like illness dropped to record lows.
For the entire 2020-2021 flu season, Michigan recorded just 10 influenza-associated hospitalizations across Clinton, Eaton, Genesee, Ingham and Washtenaw counties, compared with 948 the previous year.
Now, as another flu season arrives and highly contagious COVID-19 variants spread, infectious disease experts’ concerns have renewed.
“Last year was an anomaly,” said Subhashis Mitra, interim division chief of infectious diseases at Michigan State University. “We are expecting, with everything opening up, the flu activity to be a little more than a usual year.”
Scientists agree that pandemic safety measures such as masking, social distancing, and school closings were instrumental in limiting the transmission of all airborne viruses, not just COVID-19. To a lesser extent, experts also have cited a U.S. record number of vaccine doses administered and an overall decrease in travel as limiting factors.
Mitra emphasized the role that pandemic measures played in the decline. With governments rolling back mask mandates and social gathering restrictions, as well as the return of in-person schooling, far fewer people are now engaging those measures, which he said gives both illnesses more chances to spread.
“There is a pandemic fatigue, virus fatigue — whatever you want to call it,” Mitra said. “You have fewer people following the masking as much as I’d seen last year, so there is obviously more transmission.”
Rebecca Schein, a pediatric infectious disease doctor at MSU, said local hospitals are already seeing the consequences of mask mandates being dropped, but with a different airborne virus: respiratory syncytial virus, or RSV, for which there is no vaccine yet.
RSV is a respiratory virus that is most serious for young children and older adults. It can cause bronchiolitis, a lung infection that results in airway inflammation and congestion.
Typically, Schein said, RSV infections peak in the winter. This year, she said cases have been on the rise since June. Michigan’s statewide mask mandate ended July 1.
“The pediatric side of hospitals are full right now with children with respiratory viruses that are not all COVID,” Schein said. “Last year, because of the universal precautions that were in place, we didn’t really see viruses. But that is no longer the case.”
Here are the doctors’ answers to more questions about the coming flu season:
How bad is this year’s flu season likely to be?
So far, it’s unclear how potent this year’s flu strain is.
Typically, the Centers for Disease Control publishes an interim flu vaccine effectiveness report about mid-February. The report offers data on how successful the annual shot has been at preventing serious complications and overall risk.
However, Mitra said this year’s flu could be more harmful just because of how little flu activity there was last year.
In a normal flu season with higher rates of transmission, Mitra said people are more likely to develop antibodies as a result of becoming infected, regardless of whether or not they experienced symptoms. Because of last year’s low level of spread, fewer people possess those antibodies now, leaving more people vulnerable to the virus.
“We don’t have the protection from last year,” Mitra said
This article originally appeared in the Lansing State Journal. Read more here.back to blog