In 2019, during the third week of December, the CDC reported that 16% of samples were positive for influenza A. During the same week in 2020, the rate was 0.3%.The question, of course, is why SARS-CoV-2 continues to spread like wildfire when so many other viruses have been crushed. Viruses that have circulated for years are endemic. Because many of us have previously been exposed and therefore have developed immunity to them, social distancing can more easily cut the chain of transmission. Social distancing is probably not the only factor suppressing endemic pathogens. Walgreens, for instance, has seen “unprecedented demand” for flu vaccine shots this season

2021-06-03: Flu clade extinction?

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 1 of the H3N2 clades may have gone extinct. The same phenomenon may also have occurred with 1 of the 2 lineages of influenza B viruses, known as B/Yamagata. “Without doubt this is definitely going to change something in terms of the diversity of flu viruses out there. The extent to which it changes and how long it stays changed are the big question marks. But we have never seen this before. I do think we’re likely to lose a little bit of the H3N2 diversity. That’s a great thing. Currently when we make recommendations for vaccine strains, it’s always the headache virus.”

• Uncategorized