While masks most likely prevent community spread of COVID-19, this highly flawed paper provides no evidence on mask effectiveness at the population level. The study also provides no information to demonstrate that airborne transmission-- let alone “long-range airborne transmission”-- is…

This study provides credible estimates that by May 4, 2020, the 11 European countries in this study had achieved control of the COVID-19 epidemic by bringing the reproduction number below 1, after 3.2% to 4.0% of the population had become…

This case-control study from Spain and Italy, available as a preprint and thus not yet peer reviewed, provides the first large-scale evidence of host genetic influence in severe COVID-19 disease, and identifies biological targets for further investigation. This analysis was…

To date, there is no evidence from randomized trials regarding the effect of wearing face masks on the risk of acquiring infection from SARS-CoV-2. In the absence of this urgently needed data, this systematic review and meta-analysis provides evidence, with…

Using daily laboratory-confirmed case counts, this study evaluated the association between control measures implemented in China and the spread of COVID-19 beyond Wuhan. Control measures such as the Wuhan travel ban and implementation of Level 1 Emergency response were associated…

During the first seven weeks of a symptom monitoring program for inbound travelers to the United States from China and Iran, the California Department of Health reviewed and forwarded 12,061 traveler records, many containing errors or omissions, to 51 health…

Correctional/detention facilities are at greater risk of COVID-19 outbreaks due to the confined physical spaces, high contacts between inmates, and logistical and security issues that make it difficult to implement recommended distancing measures. This study does not report details of…

Among 18,401 users of a symptom-tracking app in the UK and US, the loss of smell and taste (as well as cough, fatigue, and skipped meals) was strongly associated with a positive SARS-CoV-2 test result. Although a symptom-based predictive model…

In this study available as a preprint and thus not yet peer reviewed, social distancing in the 25 U.S. counties with highest COVID-19 incidence was correlated with a decrease in the growth rate of COVID-19 cases, with an estimated 9…

An online survey published as a preprint and thus not yet peer-reviewed, found that US adults expressed a high willingness to test for COVID-19 at home, at drive-through test sites, and at clinics if they developed illness symptoms, with a…

Early evidence from a large online survey conducted in four European countries and the United States suggests a high willingness to install or keep a digital contact tracing application on a mobile device, with few differences across sub-populations (i.e., age,…

Preliminary results from this study of real-time COVID-19 symptom data collected through an app suggests that app-based symptom tracking may be useful for predicting spikes and drops in new cases several days in advance of other more traditional measures (e.g.…

This study used comprehensive data from China on population mobility patterns and SARS-CoV-2 case detection to estimate the individual and combined impact of non-pharmaceutical interventions (NPIs) on SARS-CoV-2 spread. Results showed that rapid detection and isolation of cases through contact…

In a survey of households in China in which one member was diagnosed with COVID-19, mask use — both by the infected individual and by uninfected family members, both before and after symptom onset — appeared to provide protection against disease…

This is an important non-peer reviewed study with important flaws. The question of whether children infected with SARS-CoV-2 can transmit the infection as readily as adults is crucial to decisions about school closures and societal re-opening. Although the authors report…

Adolescents and young adults, particularly those aged 20-24 years, represented an increasing share of reported COVID-19 cases in Germany during late March and early April, 2020. Although results are consistent with this age group exhibiting less adherence to social distancing…

As a result of social distancing measures, total interpersonal contacts dropped significantly in China, and mixing among school-aged children was almost entirely eliminated. The study estimates that school closures by themselves would reduce peak incidence by a considerable amount, though…

California has experienced a lower COVID-19 case and mortality burden relative to other states (e.g., New York) with early community transmission, leading to speculation about the role of statewide policy in the evolution of the epidemic. These results suggest that…

This study evaluated the effect of the Wuhan travel ban on the spread of COVID-19 within Mainland China and internationally. Using airport closures and airline suspensions, results from this model suggest that reducing long-range travel from Wuhan by up to…

This study convincingly shows that a large, diverse package of surveillance and containment measures effectively suppressed transmission of both COVID-19 and influenza in Hong Kong. However, it is not possible to disaggregate effects of any particular intervention, which limits the…

Local, state, and national policies designed to encourage physical distancing preceded substantial but variable reductions in the percentage of residents leaving home each day in New York, San Francisco, Seattle, and New Orleans. The marginal impacts of these policies on…

This study estimated that a coordinated, nationwide policy encouraging individuals to stay at home would have considerably decreased the number of COVID-19 cases in the US. Stay-at-home and shelter-in-place ordinances likely achieved peak effectiveness in mitigating COVID-19 transmission nearly one…

Statewide social distancing measures in the United States have been effective at reducing the daily growth rate of COVID-19, but further analyses are needed to understand which measures were most effective.

Adherence to social distancing recommendations in the United States, as measured by reductions in daily travel, was associated with socioeconomic status, race/ethnicity, and voting patterns. It is not clear how representative the data are, and unmeasured confounding may be present.

Using mathematical modeling, the authors show that containment policies and social distancing measures effectively slowed the growth in confirmed COVID-19 cases in China.

Using survey data, this study showed that in-person contacts dramatically declined following implementation of strict social distancing measures in the UK, to levels that would substantially slow epidemic growth. Participants in this study were recruited by email and may have…

This study highlights an overlooked cost of school closures: possible increases in COVID-19 mortality associated with health care workers leaving work because of increased child care burden. The model ignores several potentially important dynamics, and is reliant on assumptions with…

The severe lockdown measures put in place in Wuhan and all other cities in Hubei province in China, enacted early in the epidemic, slowed the exportation of COVID-19 from mainland China, but were insufficient to stop transmission globally. The author's…

Reduced movement in the greater Seattle area has been observed, with more people staying at home, presumably in response to the broad array of social distancing measures progressively announced since March 5, 2020. Reduced movement does not necessarily equate to…

Our take — This non peer-reviewed study found that social distancing drastically reduced transmission in Wuhan and Shanghai. Modeling suggests that school closures can significantly reduce overall transmission and disease burden, even though susceptibility to infection was lower among school-aged…

In Singapore, implementing aggressive surveillance and containment measures (e.g., compulsory quarantine for all asymptomatic close contacts) for SARS-CoV-2 was associated with a steep drop in the time between symptom onset and case isolation between the beginning of January and the…

Mobility out of Wuhan led to strong transmission chains in other parts of China. The strict ban on travel in or out of Wuhan reduced transmission in the early stage of the outbreak, when importation was the dominant source of…

This modeling study used data from China, Italy, and the UK to determine the potential impact of non-pharmaceutical interventions on the epidemic in the US and UK. Population-wide social distancing was found to be the most impactful intervention, and models…