On my way back from Turkey, and there’s nothing quite like international travel to help put things into perspective. There are much bigger problems in this world right now than the mask debate. Still, it would be tragic if people left the emergency thinking one of two extremes: “masks don’t work” or “any mask works.” Another pandemic will come, and we will need to be better and smarter. Hell, every winter, we could be smarter.
Thank you! Such awesome data! Per my personal experience, masks work! Family of four; we wore masks everywhere we went when necessary. We started out with cheap ones then got double fabric, then N95’s! We never got sick, fat maybe...lol but when we took off masks, we started getting sick. Head colds, allergies, the flu! So MASKS WORK!
What I don't understand is why the U.S., with its massive resources, has not studied the bejesus out of this question. After all the social upheaval we shouldn't have to cite Bangladeshi studies. I'm firmly pro-mask but I also am skeptical of forcing ineffective (cloth) measures on adolescents at such a social cost without proof.
Thank you for this summary. In my personal experience, and that of my family, masks work! We all wear KF94 masks and have not gotten covid. The kids attend school, birthday parties, etc. We are out in the world and even though most people around us no longer wear masks we continue to be very well protected (as evidenced by no COVID).
Thank you! I wear an well-fitting N95 everywhere and believe it reduces (not eliminates) the chances I will catch or transmit COVID. Data supplied seems to support this. I don't want to be a vector in the chain of transmission. I'm sad to see masks not required in certain settings like Memory Care facilities. The staff and visitors are not masked in Memory Care and they continue to have outbreaks, currently the SIXTH outbreak where my loved one resides. And outbreaks are hard to control in this setting and extremely hard on this population. I wrote to my local Public Health department about this topic.
> “no evidence of a difference” is different from “evidence of no difference.”
Such a critical distinction that it seems too many people either don't understand, or choose to conveniently ignore. My 10th grade geometry teacher (who taught logic as part of proofs) would hand out failing grades to a large percentage of the population...
The real problem is that the genie is out of the bottle with "proof" that requires advanced knowledge of statistical tests and measures (such as risk-ratios) and use of RCTs to be able to critically examine the conclusions that most people just don't have. That "study" was riddled with methodological issues, which can be read here https://theconversation.com/yes-masks-reduce-the-risk-of-spreading-covid-despite-a-review-saying-they-dont-198992
The vast majority of evidence (obviously inconclusive due to data limitations but still suggestive) points to masks absolutely working to reduce transmission in real-life settings which you have pointed out. It doesn't take a genius to know if you are coughing/sneezing/feeling like crap and you feel compelled to be in a crowded indoor setting that a mask would help to reduce the spread of your spit. It's why we teach preschoolers to cover their face with their arms when they are coughing or sneezing. I cannot help be astounded by the push back that still exists (and has indeed seemed to grow) on this issue and the stigmatization of this extremely non-invasive and easy intervention. But then again people fought against seat belts and not being able to drink and drive so there's that.
Thank you Katelyn for your thorough review of the mask question. I am a retired surgical pathologist, and throughout the pandemic I have often wondered about aerosol and droplet contamination from virus contaminated ambient air to a person’s eyes. I may have missed this being addressed, but I have not seen this discussed much. Adherence of the air borne viral particles to the conjunctiva of the eyes and subsequently via tears down through the nasolacrimal ducts to the nasal cavity and its mucous membranes seems a likely transmission mode that would circumvent even N95 mask protection. Perhaps personal Rx eyeglasses or safety glasses would intervene to some degree in the movement of the viral particles to the eyes. Your thoughts on this would be greatly appreciated.
I'm sorry but the "it depends" seems disingenuous. Masks work to reduce COVID writ large, period. Individual masking leads to societal reduction in infections, and societal reduction of infection leads to each person getting sick less. Communal action leads to individual benefit.
Too bad the rest of the world doesn't understand the complexity of the issue. I knew from Day One, only I could protect myself, so I always followed the most recent recommendations on how to wear a mask, what type of mask should be worn etc.
I was in a group that made over 50,000 masks. At the time, it was the best protection. Now I wear a KN95 (I'll accept the slightly higher risk vs an N95 as I am very careful, you get it.) Look at 100 people wearing a mask-we KNOW few are wearing it properly, wearing a high quality mask, wearing it consistently etc.. I DO know neither hubby nor I have had symptomatic Covid. Family and friends who were nearly religious about avoiding covid and GOT covid could point to a specific incident when they knowingly (and understandably) let their guard down.
After 3+ years and being fully vaxed and boosted, I too sometimes let my guard down, evaluate the risk and will expand my activities. So, I know it's more likely I'll get Covid, but I'll still try to avoid it while expanding my life and improving my mental health.
People tend to deny a simple truth about the world: it's all about probability and outcome (watch the 1978 movie "Heaven Can Wait" for an amusing take). Your question, in my mind, has been asked and the outcome provides the answer: populations where the societal norm was to wear a mask (no matter how effective) did much better than those lacking that norm.
Great post. Neat as a pin. Nicely constructed. Too bad that the talking heads on cable TV news shows will very likely never be able to: (a) Comprehend why this is a great post that was nicely constructed and neat as a pin OR (b) Provide any refreshing "clean-up" of this issue for lay folks.
Thank you for providing this arc in how thinking has evolved around the value of wearing masks as new information became known.
I’m still masking, and I hate it but do it anyway. Is it fair to say, that when a virus is extremely contagious, masks primarily *delay* infection, but sooner or later, if you’re out and about enough, even if you’re wearing the right mask, you’re going to get Covid? All it takes is one unlucky airplane ride or jury duty sitting next to the wrong person?
Also, I’m headed to London soon and hear cases are on the rise again in the UK. So why are they ending the bivalent booster? Seems like odd timing.
So, folk have posted pro and con regarding mask wearing which I have found wearing! Logic tells me the following: Covid is mainly transmitted through droplets and is highly contagious; putting a barrier between me and those droplets would seem to be the most logical and simple solution! Hence, I remain a Covid "virgin" as they say. I have had numerous very close, inside exposures- even with someone coughing and sneezing mask less right next to me! I ALWAYS wear a KN94 mask to all inside activities...especially as I have received numerous, post meetings, emails apologizing for exposing me..and my immune-compromused husband thru me...to Covid! Aarrgg...I don't need RCTs to tell me what logic says: wear a mask and stay safe! Will I ever attend a meeting ( and I have to go to many) in the future without a mask....that all will depend upon the efficacy of future vaccines for this ( I am fully vaccinated as well). My family has also not had any flu or colds since we started masking. It's just LOGICAL! So, thank you Katelyn for attempting to share the science- but the logic wins by a landslide for me.
One factor you didn't include is the buffering effect on an epidemic in a community. If you think that (say) 90% of the community will get the disease without masks (in a short time frame) or with masks (spread out over a longer time frame), then wearing masks appears to spread out the peak of infections, allowing the community to minimize overwhelming its health care. Even if everyone gets the disease eventually, fewer would be infected during times when health care was less efficient.
Also, in this novel disease, if an individual can postpone his/her own infection, then he/she has a better chance that some miracle prevention or treatment will improve his/her outcome.
Re Meta-analysis and the distinction between no evidence of benefit vs. evidence of no benefit, see:
Smith & Pell. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. BMJ 2003; 327 doi: https://doi.org/10.1136/bmj.327.7429.1459
Because we're at high risk for a bad Covid outcome, we don't do the following things indoors, and we'd like to know if it's safe to start doing them with a KN95 or N95 on, assuming almost everyone else is unmasked, it is probably crowded and distancing impossible, and there may not be good air circulation: ride the subway; go to a play, dance performance, art opening, meeting, or similar event or party; get a haircut at a salon; sing with other people; exercise with other people.