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Coronavirus Precautions Rub Out Flu Bugs, Make Vaccine Choices Easier for Coming Seasons

Even South Dakota’s lazy and irresponsible response to the coronavirus pandemic has contributed to the near eradication of flu this season in our fair state. Our masking and social distancing may also have saved lives for years to come, thanks to the apparent extinction of certain strains of flu:

With Covid suppression measures like mask wearing, school closures, and travel restrictions driving flu transmission rates to historically low levels around the world, it appears that one of the H3N2 clades may have disappeared — gone extinct. The same phenomenon may also have occurred with one of the two lineages of influenza B viruses, known as B/Yamagata.

Neither has been spotted in over a year. In fact, March of 2020 was the last time viral sequences from B/Yamagata or the H3N2 clade known as 3c3.A were uploaded into the international databases used to monitor flu virus evolution, Trevor Bedford, a computational biologist at the Fred Hutchinson Cancer Research Center in Seattle, told STAT [Helen Branswell, “A Pandemic Upside: The Flu Virus Became Less Diverse, Simplifying the Task of Making Flu Shots,” Stat, 2021.06.02].

Fewer strains of flu means vaccine makers don’t have to try piling as many strains into each year’s vaccine. Vaccines can’t take on every strain, so the vaccine makers have to guess which strains they think will be most prevalent and deserve the strongest fight:

SHAPIRO: And so I guess each year the people who develop flu vaccines sort of have to – I don’t know – make an educated guess about which strains are going to be circulating that year. And if they’re wrong – I mean, you report that in a recent year, up to three quarters of people who got the shot actually were not immunized against the flu.

BRANSWELL: Yeah. So what they have to do is sort of look within each class of viruses to see which strains are the most dominant. But they’re doing it months in advance. Like, for our flu shot in the Northern Hemisphere, they’re deciding in February what should go into the flu shot we’re going to get the following autumn. So they have to look and see what seems to be dominant, what seems to be receding and make some choices. But it’s been very hard in recent years, particularly with H3N2 viruses because they’ve been so diverse. And knowing which is going to be the dominant strain the next winter has been really tough. But it now seems like, you know, the diversity has been diminished because there’s been so little circulation of the viruses [Ari Shapiro interviewing Helen Branswell, “Certain Strains of Flu May Have Gone Extinct Because of Pandemic Safety Measures,” NPR: All Things Considered, 2021.06.03].

If you hear folks arguing that taking serious measures to prevent the spread of coronavirus has produced more costs than benefits, ask them if they are including the benefits of crushing the flu virus this season and possibly reducing the flu death toll for years to come.

11 Comments

  1. Donald Pay 2021-06-04 08:29

    Wearing a mask during flu season has been a feature of life in Asia for a while. Mask wearing is a polite thing to do if you have sniffles or a cough in east Asia countries. It helps prevent or slow down transmission of flu.

    Asia wildlife, particularly wild birds, and poultry is a reservoir of various flu strains. New ones break out every few years in poultry and then a few cross over into humans or swine.

    A recent case of a new influenza bears watching. My daughter follows this stuff pretty routinely because of her work following China’s ag industry. Here’s a link to an article about this new flu:

    https://www.reuters.com/business/healthcare-pharmaceuticals/china-reports-human-case-h10n3-bird-flu-2021-06-01/

  2. cibvet 2021-06-04 09:21

    First two winters as far back as can remember without catching a cold. Unsure if it was the mask or just avoiding sick people who don’t care about spreading disease, but it has been a pleasant two winters.

  3. Donald Pay 2021-06-04 09:57

    My experience is similar to cibvet. I did have one cold, but that’s down from the three or four I usually have in that time frame. Also, I found my allergies symptoms weren’t as severe as usual. My hypothesis is that the mask filtered out some of the tree pollen that usually sets off my symptoms.

  4. mike from iowa 2021-06-04 12:01

    But, but covid is the flu, wah! You can get vaccinated against the flu.

  5. leslie 2021-06-04 13:52

    Ryan, if i recall, early on made a big deal out of measles high R factor in comparison to what CO-19 has. Without the mutation variation makes covid so difficult, according to Fauci today, and thus as i supposed, is “north” of measles.

  6. Porter Lansing 2021-06-04 18:46

    Colds seem to come from exposure to children who naturally are in close contact with each other.

    Having kids staying home may have been the reason colds were infrequent during Covid.

  7. DaveFN 2021-06-04 19:51

    Poultry, pigs, kids, or adults—-vectors are vectors, a reproductive playground in this case for a virus.

  8. grudznick 2021-06-04 20:26

    Mr. Lansing is tighter than right. Those darned kids should have to stay home all the time, even when all the covid bugs are dead. We don’t need those germy little snot nosed criers out in public annoying everyone and posing a public health nuisance.

  9. Cory Allen Heidelberger Post author | 2021-06-05 06:46

    I’m not a big socializer as it is, but a good year-plus of not dining out, going to the store less frequently, and otherwise keeping my distance more than usual appears to have kept colds away from my house, too. As a pastor, my wife has more close contact with more people than I do as a college registrar, but she also saw reduced contact and reduced illness. My daughter went to school for an hour each day of orchestra and thus interacted closely with a smaller cohort of young disease vectors. Orchestra players are more sensible than the rest of the population, so her exposure to pathogens was significantly reduced as well.

  10. leslie 2021-06-05 09:25

    Funny this is just how i visualize grdz at his “common” sense red neck greezy spoon:

    “germy snot nosed criers out in public annoying everyone and posing a public health nuisance.”

  11. cibvet 2021-06-05 23:13

    Well put, leslie.

Comments are closed.