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Comment by brenden2 | Hacker News Reader

Is there any real evidence that masks provide any value for healthy people (excluding health care workers)? All I've seen are anecdotes from internet armchair experts.

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The parent link has a link to a list of papers[1] that answer this question in the affirmative:

For example, "Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population" [2]

It's also worth noting that many people with COVID-19 are asymptomatic, so wearing a mask, even a homemade one, could reduce the spread to other healthy people.

[1] https://docs.google.com/document/d/1HLrm0pqBN_5bdyysOeoOBX4p...

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/

Scientific papers studying and summarizing the utility of masks, from the article: https://docs.google.com/document/d/1HLrm0pqBN_5bdyysOeoOBX4p...

I think part of the issue in this case is that no one knows if they are "healthy." You could be transmitting the disease while still asymptomatic yourself.

"Most cases of severe acute respiratory syndrome (SARS) have occurred in close contacts of SARS patients. However, in Beijing, a large proportion of SARS cases occurred in persons without such contact. We conducted a case-control study in Beijing that compared exposures of 94 unlinked, probable SARS patients with those of 281 community-based controls matched for age group and sex. Case-patients were more likely than controls to have chronic medical conditions or to have visited fever clinics (clinics at which possible SARS patients were separated from other patients), eaten outside the home, or taken taxis frequently. The use of masks was strongly protective. Among 31 case-patients for whom convalescent-phase (>21 days) sera were available, 26% had immunoglobulin G to SARS-associated coronavirus. Our finding that clinical SARS was associated with visits to fever clinics supports Beijing's strategy of closing clinics with poor infection-control measures. Our finding that mask use lowered the risk for disease supports the community's use of this strategy."

https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article

Yes! The page links to this document, which gives what appears to be a fairly comprehensive review of the literature: https://docs.google.com/document/u/0/d/1HLrm0pqBN_5bdyysOeoO...

Yes. They provide value by protecting others from you. You don't know if you're "healthy" because even asymptomatic or pre-symptomatic cases are contagious. You wear the mask to protect others, not yourself. Others wear masks to protect you.

I don't see what a persons profession has to do with whether or not a mask protects against a virus or not? The difference is exposure not efficacy of the tool.

It's all linked on the website: https://tiny.cc/maskswork

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3373043/

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