"The Flu Vanished During Covid. What Will Its Return Look Like?"
By Keith Collins
New York Times
https://www.nytimes.com/interactive/2021/04/22/science/flu-season-coronavirus-pandemic.html
The NYT & virologist Dr. Richard Webby
https://www.stjude.org/directory/w/richard-webby.html
have some observations, including this curious one:
"When the reality of the coronavirus pandemic set in last year, the country was still in the throes of the normal flu season, which had peaked in February. Then schools closed, travel halted and millions began working from home, and the number of new flu cases quickly dropped to historic lows, even as the coronavirus surged…"
"'The mere presence of the coronavirus may have also played a role in suppressing flu cases,' said Dr. Webby, 'because there is often just one dominant respiratory virus in a population at a given time. One tends to keep the other out,' he said."
"And influenza was not the only virus that disappeared over the last year; there were also substantial drops in other respiratory illnesses, including the respiratory syncytial virus, or R.S.V., which is the most common cause of pneumonia in infants."
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So according to Dr. Webby, infection by one "dominant respiratory virus" can prevent infection by multiple respiratory viruses.
Is that common knowledge? It would seem important.
Hmm… Some open questions…
1. Has this "replacement" effect been documented in any influenza seasons prior to 2020? And has the effect been seen to extend through two seasons, as with COVID-19?
Example: Looking at WHO data for the 2009 H1N1 flu pandemic [image], we don't see a replacement of other flu types (yellow) with H1N1 (orange), only additional H1N1 cases. So the replacement effect does not seem present during that famous recent event.
2. Is there any country where 2020 and 2021 influenza seasons persisted? If so, is there a pattern?
3. The stated replacement effect has now extended well into Year 2, or a second influenza season. This is longer than a typical flu vaccine can manage: a new vaccine is needed each year. Why should the replacement effect be more durable than a targeted vaccine?
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Dr. Webby adds:
“We’re in uncharted territory. We haven’t had an influenza season this low, I think as long as we’ve been measuring it."
Well, detailed death counts were conducted during the influenza pandemic of 1918 [image], so "measurements" would seem to go back quite a long way.
You'd think virologists must be exploring this important "uncharted territory" thoroughly, and quickly. Who's really examining the data, out there in the new pro literature? And what's been discovered with respect to the open questions above? I'm taking an amateur look, but not seeing clear info yet.
Example: Some conflicting reports and speculation from Aug. 2020:
"What Happens When COVID-19 Collides With Flu Season?"
by Rita Rubin, MA
JAMA
https://jamanetwork.com/journals/jama/fullarticle/2769835
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[Subtext: wondering how present anons et al. might approach the open questions, after recent… issues…]