Public health agencies are poised to continue promoting face masks after COVID, and the record-low incidence of influenza from 2020 to 2021 has sparked a new wave of mask promotion.
Paul Offit, M.D. the director of the Vaccine Education Center in Philadelphia and member of the FDA’s Vaccine Advisory Committee, floated the idea on CNN on March 3.
“If we mask and social distance every winter, we will see a dramatic reduction in the flu, which usually causes hundreds of thousands of hospitalizations and tens of thousands of deaths,” Offit said.
Offit referenced a graph showing cases of flu over the past two years.
“The fact that last year, at exactly this time, the positivity of flu was 30 percent,” the CNN host stated. “This year, [it is] 0.1 percent. I mean that’s got to be masks, right? And, the fact that people are social distancing.”
“That’s exactly right. I mean, typically, every year between 150 and 200 children die of influenza. This year, so far, one child has died of influenza,” Offit said. “I wonder if that will be the lesson from this.”
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and advisor to presidents Trump and Biden, previously suggested wearing masks during flu season would be beneficial. However, a May 2020 study conducted by researchers at the University of Hong Kong and supported by the World Health Organization found no evidence that face masks reduce flu transmission.
What is not in doubt is that flu cases are down this season. The CDC has said flu cases dropped in 2020 by more than 90 percent compared to 2019. The agency recorded 195 child deaths from the flu over the 2019-2020 season. This year, the CDC recorded just one.
The CDC’s analyses of mask effectiveness have shown a mixed record at best, and health officials have not recommended wearing masks to prevent flu spread in the past.
Regardless, some states are setting their mask mandates in stone, requiring future legislative action to undo them. Oregon’s Occupational Safety and Health Administration recently revealed a plan to make the state’s mask mandate, in place since November, permanent. Michigan’s equivalent bureaucracy announced it is working on a similar plan.
Cause or Correlation?
Although it is easy to connect mask-wearing and reduced incidence of influenza, there are “many” other potential explanations for the decline, says Erwin Haas, M.D., an infectious disease expert and a policy advisor to The Heartland Institute, which co-publishes Health Care News.
“The flu does indeed seem to be sparse this year,” Haas said. “Flu spreads and is serious among students, [but] many of them are not in school or socializing.”
Americans have become accustomed to social distancing, voluntarily or otherwise. Many Americans switched to remote work and school. There has also been more promotion of standard hygiene measures, such as washing hands and sanitizing, which could account for some of the reduction. Additionally, more Americans received flu shots this season than the previous one.
Haas raises another possibility for reduced flu, although he cautions that he has no data to support his hypothesis.
“Influenza strains arise in China, and travel from that country has been severely restricted,” Haas said. “It would be interesting to know about what has happened in China and in adjacent countries with regard to flu in the last year. It may not have escaped.”
Yet another factor that could be contributing to the massive decline in flu cases are peculiarities in reporting. Most people who get the flu never report it or are tested for it unless they are hospitalized. So, due to incomplete information, the CDC relies on a mathematical model to estimate the flu burden on the population. The CDC also relies on collaboration with state, local, and territorial governments, adding complexity and room for error, especially when more resources are focused on COVID-19.
Haas questions the wisdom of calling for normalization of mask-wearing during flu season.
“Masks do not seem to prevent infection from spreading from either the wearer or from the exposed to the wearer,” Haas said, referencing a University of Hong Kong study. “But who knows what irrationality will prevail in the public’s eternal quest for safety at all costs.