Preventing the Spread of SARS-CoV-2 With Masks and Other “Low-tech” Interventions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), has caused a global pandemic of historic proportions in the 10 months since cases were first reported in Wuhan, China, in December 2019, with worldwide morbidity, mortality, and disruptions to society. 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 SARSCoV-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.