Is universal masking to prevent/reduce the spread of covid-19 the correct approach?Netherlands and Sweden say no.
Their position appears to be backed by science.
In May, 2020, the CDC published a meta-analysis of the evidence on the effectiveness of nonpharmaceutical personal protective measures and environmental hygiene measures in nonhealthcare settings and discuss their potential inclusion in pandemic plans.
With respect to facemasks, it concluded:
In our systematic review, we identified 10 RCTs that reported estimates of the effectiveness of face masks in reducing laboratory-confirmed influenza virus infections in the community from literature published during 1946–July 27, 2018. In pooled analysis, we found no significant reduction in influenza transmission with the use of face masks (RR 0.78, 95% CI 0.51–1.20; I2 = 30%, p = 0.25).
Disposable medical masks (also known as surgical masks) are loose-fitting devices that were designed to be worn by medical personnel to protect accidental contamination of patient wounds, and to protect the wearer against splashes or sprays of bodily fluids. There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure. Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza.
Further, as reported by the New York Times:
Even in its latest guidance, the W.H.O. made its reluctance abundantly clear, saying the usefulness of face masks is “not yet supported by high quality or direct scientific evidence,” but that governments should encourage mask wearing because of “a growing compendium of observational evidence.