Because my family is from Taiwan and I’ve spent several summers there these last few years to shove some language immersion down my children’s throats, I’m a little more used to mask-wearing culture than the average American. And thus, I was unsurprised to learn that since the start of the pandemic, the spread of almost every common respiratory and gastrointestinal virus other than COVID-19 is down. Way down.
Incidentally, as of February 4, 2021, Taiwan has had 9 COVID-19 deaths. NINE. (And to think, my relatives urged me not to come last summer out of fear for my safety when in reality, it would be the U.S. that would be so abysmally fucked.)
Epidemiologists theorize that the global shutdown and non-pharmaceutical interventions such as social distancing, mask-wearing, and hand-washing have helped with containing the coronavirus. However, other viruses such as influenza A and B, norovirus, respiratory syncytial virus (RSV), parainfluenza, and human metapneumovirus — as well as bacterial infections such as pertussis (whooping cough) and pneumonia — have all gone down in reported levels.
For perspective, in the third week of December 2019, right before COVID-19 hit the U.S., the Centers for Disease Control and Prevention (CDC) reported that 16.2% of the samples sent to its clinical lab tested positive for influenza A. During the third week of December 2020, the rate was 0.3%.
CDC Domestic Influenza Surveillance team leader Lynnette Brammer told The Washington Post, “This is my 30th flu season. I never would have expected to see flu activity this low.”
In August 2020, the CDC warned doctors and parents of another possible peak year for a rare and mysterious polio-like illness called acute flaccid myelitis (AFM). Thought to be caused by enterovirus-D68, AFM previously set a new peak every other year in the U.S. between August and November since 2014. With more than 90% of cases in young children, there were 120 cases in 2014, 153 in 2016, and 238 in 2018 — but only 29 in 2020.
In that same Washington Post article, pediatric infectious-disease physician Kevin Messacar at Children’s Hospital Colorado in Aurora said, “We haven’t had any specimen positive for [enterovirus] D68 … at our site in Colorado since July, and my colleagues around the country also saw very little.” Messacar went on to say, “We also have not seen significant influenza or RSV on our wards in Colorado. All the most common childhood infections that land children in the hospital — influenza, croup, bronchiolitis — we are not seeing.”
Non-pharmaceutical interventions are not the only factors making a difference
To me, it’s just common sense. If you mask up like a courteous, community minded, unselfish person, of course any kind of sickness will stop spreading. It’s like oh, of course social distancing and washing your hands frequently will reduce infections. Thanks, Captain Obvious.
But as it turns out, I’m only partially right. (Someone screenshot this because this will likely be the last time you read such a sentence. Oh wait, nevermind. We should normalize admitting when we’re wrong.)
Yes, the social distancing and other protocols are part of the reason, but they’re not the only reason.
Increased flu vaccinations
Turns out, more adults in 2020 decided to get the flu vaccine as compared to previous years — although some groups have had lower rates of flu vaccinations such as non-Hispanic Black adults and children. As of January 1, 2021, there have been a record number of 192.5 million flu doses distributed in the U.S. during a single flu season, likely helped by community flu vaccinations starting earlier than usual in 2020 in preparation.
Less international travel
Even in countries with less robust COVID-19 controlling protocols, there has been a decrease in flu rates, too. St. Jude’s hospital virologist Richard Webby in Memphis, Tenn. told Nature that he suspected the lack of international travel played a role since the flu typically circumnavigates the world, chasing winter from one hemisphere to another while being low-key year-round in the tropics.
According to a study published in October 2020, being infected by one virus can trigger your immune system to release interferons, which block the abilities of viruses to replicate. In the case of this study, they found that one respiratory virus infection can block another because it stimulates the antiviral defenses in airway mucosa. In other words, because patients had contracted a rhinovirus infection before, it lowered the chances of them also contracting influenza A. This supported the theory that the rhinovirus impeded the 2009 influenza A pandemic in Europe.
Viral interference may also help explain why so few children are getting ill from the coronavirus. It turns out, one of the only common viruses still being passed around is the rhinovirus — i.e.: the common cold — but mostly only in children.
If other viral infections are down, how come there’s still a pandemic?
So if all our precautions are causing sharp declines in all the other viruses, why is COVID-19 still spreading? Shouldn’t these same factors also cause the coronavirus to chill the fuck out?
Well, here’s the bad news (followed by maybe some more bad news). All these rhinoviruses, enteroviruses, and other viruses we routinely got and spread around to each other? Turns out, it’s because they’re always around and very common (endemic) — and because of this, many of us had already been previously exposed and developed immunity to them. Our wearing masks and not going into work or school sick and social distancing could thus more easily stop the spread.
But COVID-19? That’s a novel coronavirus — meaning it’s totally new. Our bodies aren’t used to it yet and haven’t had years to build up defenses. As a result, it’s much more difficult to break the chain of infection and requires much more stringent social distancing.
But wait, there’s more!
Because we’re social distancing and not getting infected with these more common viruses, epidemiologists are worried that this extended non-exposure will cause a decrease in herd immunity and thus increase outbreaks of these endemic viruses once we ditch the face masks and go back to business as usual. But of course, since it’s never happened in our lifetimes before, they really don’t know.
Personally, I am all for some of the social distancing changes to stay for good after the pandemic passes into the endemic and manageable. All those curbside pickups and increased delivery options? More, please.
As for masks? I’m going to take a page from my Taiwanese family and incorporate masks into our family’s lifestyle from here on out.