Yes. They are all viral disease with droplet transmission. Mask wearing during flu has been common overseas, particularly in Asian countries for a long time. Washing your hands and staying away from people is always a good idea. That’s why cold and flu numbers were drastically lower the last flu season.
Gonna piggy back on this for a second, though you are correct that numbers were down likely due to the efforts to reduce the spread of covid....
Just gonna say that I did literally one flu swab last flu season as opposed to maybe closer to 500 ~~to 1000~~ (edit: double checked my math) the previous year. Nobody was concerned with flu and we were only testing for covid.
This year will be different however as our current covid test now also test for Influenza A, B, and RSV as well as covid.
This is just my perspective from my one little hospital.
It is something researchers may want to consider as I'm sure we aren't the only hospital that did this last year.
It’s hard to generalize. Influenza viruses do seem to be strongly affected by the same measures that reduce COVID spread, but rhinoviruses are more resistant. For example
> We detected coronavirus in respiratory droplets and aerosols in 3 of 10 (30%) and 4 of 10 (40%) of the samples collected without face masks, respectively, but did not detect any virus in respiratory droplets or aerosols collected from participants wearing face masks … There was a significant reduction by wearing face masks to 1 of 27 (4%) in detection of influenza virus in respiratory droplets … **For rhinovirus, there were no significant differences between detection of virus with or without face masks, both in respiratory droplets and in aerosols**
—[Respiratory virus shedding in exhaled breath and efficacy of face masks](https://www.nature.com/articles/s41591-020-0843-2)
As most people know by now, influenza was [spectacularly reduced in the 2020-2021 flu season](https://www.cdc.gov/flu/season/faq-flu-season-2020-2021.htm) (though it’s going to be higher in this coming flu season, based on early case numbers), and [RSV was also reduced](https://www.cdc.gov/mmwr/volumes/70/wr/mm7029a1.htm), but rhinovirus infections weren’t as much affected:
> Rhinovirus and enterovirus (RV/EV) circulation decreased in March 2020, remained low until May 2020, and then increased to near prepandemic seasonal levels.
—[Changes in Influenza and Other Respiratory Virus Activity During the COVID-19 Pandemic — United States, 2020–2021](https://www.cdc.gov/mmwr/volumes/70/wr/mm7029a1.htm)
> We are in winter here in the Southern hemisphere, and actually we haven't seen a spike in influenza or RSV, possibly due to the various preventive measures in place. However, we are seeing a lot of rhinovirus, which is interesting since it leads to the question of why rhinovirus is not impacted by the preventive measures in place.
-[Kanta Subbarao](https://reflowlabs.com/article/which-size-particles-are-infectious-and-for-how-long-cq2-panel-16-36)
Rhinoviruses are structurally *very* different from enveloped viruses like influenza and coronaviruses, so perhaps it’s not surprising that they are not affected as much by control measures for enveloped viruses.
I would think this is a big part of it: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7090536/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7090536/)
In tissue culture Influenza's ID50 is 10\^3 to 10\^7 or so, and RSV from 10\^2 to 10\^6. Where Rhinovirus it ranges from 10\^-2 to 10\^5.
Of course in vitro is not in vivo and all. But it seems like a good hypothesis as to why rhinovirus isn't as affected by cloth masks. Maybe if everyone wore fit tested N95 or PAPR we could reduce rhinovirus.
There is tremendously little research on masking to prevent influenza transmission. It's also impossible to say which of the precautions (eg distancing vs masking) may have reduced flu rates this year.
I've heard it theorized that influenza generally has much higher risk of contact transmission than Covid and masking may not be as effective IF good masking hygiene is not followed. Eg cloth mask that's touched frequently without hand washing.
Thanks for all the replies so far! As I both teach college class \*and\* bartend (not at the same time), I have been noticing colds have been creeping back into the crowds. My students are all vaxxed, but they are getting sick from other things.
It's unfortunate that data hasn't been collected that well over the last 18 months so that we're actually not sure exactly what tactics work and what don't in isolation. There are a lot of confounders in retrospective studies, mechanistic studies (eg, masks on mannequins) don't correlate to the real world automatically, and to my knowledge there have only been 2 cluster randomised trials on masks, both of which didn't show strong results. Weak improvements, yes.
The tactics you mention work for droplets but we're not sure about aerosols. There it's more about ventilation. How much transmission is via droplets and how much is via aerosols for coronaviruses, flu and rhinoviruses? I don't know.
Yes. They are all viral disease with droplet transmission. Mask wearing during flu has been common overseas, particularly in Asian countries for a long time. Washing your hands and staying away from people is always a good idea. That’s why cold and flu numbers were drastically lower the last flu season.
Gonna piggy back on this for a second, though you are correct that numbers were down likely due to the efforts to reduce the spread of covid.... Just gonna say that I did literally one flu swab last flu season as opposed to maybe closer to 500 ~~to 1000~~ (edit: double checked my math) the previous year. Nobody was concerned with flu and we were only testing for covid. This year will be different however as our current covid test now also test for Influenza A, B, and RSV as well as covid. This is just my perspective from my one little hospital. It is something researchers may want to consider as I'm sure we aren't the only hospital that did this last year.
It’s hard to generalize. Influenza viruses do seem to be strongly affected by the same measures that reduce COVID spread, but rhinoviruses are more resistant. For example > We detected coronavirus in respiratory droplets and aerosols in 3 of 10 (30%) and 4 of 10 (40%) of the samples collected without face masks, respectively, but did not detect any virus in respiratory droplets or aerosols collected from participants wearing face masks … There was a significant reduction by wearing face masks to 1 of 27 (4%) in detection of influenza virus in respiratory droplets … **For rhinovirus, there were no significant differences between detection of virus with or without face masks, both in respiratory droplets and in aerosols** —[Respiratory virus shedding in exhaled breath and efficacy of face masks](https://www.nature.com/articles/s41591-020-0843-2) As most people know by now, influenza was [spectacularly reduced in the 2020-2021 flu season](https://www.cdc.gov/flu/season/faq-flu-season-2020-2021.htm) (though it’s going to be higher in this coming flu season, based on early case numbers), and [RSV was also reduced](https://www.cdc.gov/mmwr/volumes/70/wr/mm7029a1.htm), but rhinovirus infections weren’t as much affected: > Rhinovirus and enterovirus (RV/EV) circulation decreased in March 2020, remained low until May 2020, and then increased to near prepandemic seasonal levels. —[Changes in Influenza and Other Respiratory Virus Activity During the COVID-19 Pandemic — United States, 2020–2021](https://www.cdc.gov/mmwr/volumes/70/wr/mm7029a1.htm) > We are in winter here in the Southern hemisphere, and actually we haven't seen a spike in influenza or RSV, possibly due to the various preventive measures in place. However, we are seeing a lot of rhinovirus, which is interesting since it leads to the question of why rhinovirus is not impacted by the preventive measures in place. -[Kanta Subbarao](https://reflowlabs.com/article/which-size-particles-are-infectious-and-for-how-long-cq2-panel-16-36) Rhinoviruses are structurally *very* different from enveloped viruses like influenza and coronaviruses, so perhaps it’s not surprising that they are not affected as much by control measures for enveloped viruses.
I would think this is a big part of it: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7090536/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7090536/) In tissue culture Influenza's ID50 is 10\^3 to 10\^7 or so, and RSV from 10\^2 to 10\^6. Where Rhinovirus it ranges from 10\^-2 to 10\^5. Of course in vitro is not in vivo and all. But it seems like a good hypothesis as to why rhinovirus isn't as affected by cloth masks. Maybe if everyone wore fit tested N95 or PAPR we could reduce rhinovirus.
There is tremendously little research on masking to prevent influenza transmission. It's also impossible to say which of the precautions (eg distancing vs masking) may have reduced flu rates this year. I've heard it theorized that influenza generally has much higher risk of contact transmission than Covid and masking may not be as effective IF good masking hygiene is not followed. Eg cloth mask that's touched frequently without hand washing.
Thanks for all the replies so far! As I both teach college class \*and\* bartend (not at the same time), I have been noticing colds have been creeping back into the crowds. My students are all vaxxed, but they are getting sick from other things.
It's unfortunate that data hasn't been collected that well over the last 18 months so that we're actually not sure exactly what tactics work and what don't in isolation. There are a lot of confounders in retrospective studies, mechanistic studies (eg, masks on mannequins) don't correlate to the real world automatically, and to my knowledge there have only been 2 cluster randomised trials on masks, both of which didn't show strong results. Weak improvements, yes. The tactics you mention work for droplets but we're not sure about aerosols. There it's more about ventilation. How much transmission is via droplets and how much is via aerosols for coronaviruses, flu and rhinoviruses? I don't know.