Masks and other health practices will still be needed for a while after vaccines--paper by Dr Fauci and colleagues

Preventing the Spread of SARS-CoV-2 With Masks and Other “Low-tech” Interventions In this Viewpoint, Anthony Fauci and colleagues at NIAID emphasize the continued importance of low-tech public health practices, such as wearing masks, limiting large gatherings, hand washing, and physical distancing, to help control the COVID-19 pandemic even after safe and effective vaccines... JAMA_current

Ultimately, a safe and effective vaccine will be essential to control the pandemic and allow resumption of the many activities of normal life. While results of phase 3 trials for multiple candidate vaccines are on the near horizon, “low-tech” tools to prevent the spread of SARS-CoV-2 are essential, and it must be emphasized that these interventions will still be needed after a vaccine is initially available. Even if one or more vaccines have high efficacy and uptake in the population, it will take at least several months for enough people to be vaccinated to confer herd immunity on a population basis.

Modalities in the combination prevention “toolbox” against the spread of SARS-CoV-2 include wearing masks, physical distancing, hand hygiene, prompt testing (along with isolation and contact tracing), and limits on crowds and gatherings. If a vaccine has only moderate efficacy, or if vaccine uptake is low, these other modalities will be even more critical.

Wearing face coverings—masks—in the community setting to prevent the spread of SARS-CoV-2 is a key component of this combination approach. Multiple lines of evidence support the effectiveness of masks for the prevention of SARS-CoV-2 transmission. Mandates for the wearing of masks in public have been associated with a decline in the daily growth rate of COVID-19 cases in the US. The implementation of such mandates averted more than 200 000 cases of COVID-19 by May 22, 2020, according to modeling estimates.¹

Randomized clinical trials of community mask use are challenging to conduct because of ethical and practical considerations. Observational studies have substantial limitations but can be instructive. For example, a study of secondary SARS-CoV-2 transmission in 124 Chinese households found that mask wearing at home by 1 or more family members before the onset of symptoms in the primary case was associated with a lower odds of secondary transmission (adjusted odds ratio, 0.21 [95% CI, 0.06-0.79]).² In a study at a US academic medical center, after the implementation of universal mask use for all health care workers and patients, the SARS-CoV-2 positivity rate among health care workers declined from 14.65% to 11.46%, with a decline of 0.49% per day.³   ...