President Donald Trump on Saturday was photographed wearing a mask during a visit to the Walter Reed National Military Medical Center, after months of refusing to don the medical expert-recommended face coverings meant to help slow the spread of the coronavirus.
"I love masks in the appropriate locations," Trump said, speaking to reporters at the White House before his visit.
Trump's usual reluctance to cover his mouth and nose in public has been a point of controversy during the nation's coronavirus crisis, especially as cases of COVID-19 continue to spike — particularly in Republican-led states.
Before taking off for Walter Reed, Trump said he'd "probably" wear a mask.
"I think when you're in a hospital, especially in that particular setting, where you're talking to a lot of soldiers and people that, in some cases, just got off the operating tables, I think it's a great thing to wear a mask," the president told reporters. "I've never been against masks, but I do believe they have a time and a place."
Trump was at Walter Reed to visit wounded soldiers and medical professionals at the facility who specialize in coronavirus care.
The president had indicated earlier this week that he would likely wear a mask to the medical center to avoid the possibility of infecting soldiers.
"You're in a hospital setting, I think it's a very appropriate thing," Trump said during a Thursday interview with Sean Hannity on Fox News. "I have no problem with a mask. I don't think you need one when you're tested all the time, everybody around you is tested."
It’s been over six months since the coronavirus pandemic hit the U.S., and transmission continues across the country as communities open up and schools start class.
Making things worse, according to one doctor, is because of the lack of a federal policy on masks.
“It is going through the country because there's no mask mandate,” Dr. Andre Campbell, a trauma surgeon at the Zuckerberg San Francisco General Hospital, said on Yahoo Finance’s The Ticker (video above). “And there should be, in my opinion, a universal mask mandate, because data shows that we can save 70,000 lives if we mask everybody up right now. Because we're going to be, by the election and the end of the year, we're going to be north of 300,000 deaths, because about 1,000 people are dying a day from this terrible pandemic.”
There are more 6 million confirmed coronavirus cases in the U.S. and over 184,000 deaths. Those numbers are expected to keep growing, at least until there is a COVID-19 vaccine widely available.
A model from the Institute for Health Metrics and Evaluation (IHME) found that if 95% of people in the U.S. began wearing masks every time they were outside their homes, the number of projected deaths from coronavirus by December would drop 49%. That would save nearly 70,000 lives.
The Centers for Disease Control and Prevention revised its coronavirus guidance Monday, acknowledging that it can sometimes spread through airborne particles that can “linger in the air for minutes to hours” and among people who are more than six feet apart.
The CDC cited published reports that demonstrated “limited, uncommon circumstances where people with COVID-19 infected others who were more than 6 feet away or shortly after the COVID-19-positive person left an area.”
“In these instances, transmission occurred in poorly ventilated and enclosed spaces that often involved activities that caused heavier breathing, like singing or exercise,” the CDC said in a statement. “Such environments and activities may contribute to the buildup of virus-carrying particles.”
The agency added that it is “much more common” for the virus to spread through larger respiratory droplets that are produced when somebody coughs, sneezes, sings, talks, or breathes. People are infected through such droplets mostly when they are in close contact with an infected person, the CDC said.
“CDC’s recommendations remain the same based on existing science and after a thorough technical review of the guidance,” the agency said. “People can protect themselves from the virus that causes COVID-19 by staying at least 6 feet away from others, wearing a mask that covers their nose and mouth, washing their hands frequently, cleaning touched surfaces often and staying home when sick.”
The updated guidance comes after the agency mistakenly posted a revision last month that said the virus could spread through aerosols, small droplets that can linger in the air. The guidance was quickly removed from the CDC’s website because it was just “a draft version of proposed changes,” the agency said.
To what degree the coronavirus can spread through airborne particles has been a contentious debate among scientists for months. Some epidemiologists have charged that the World Health Organization as well as federal regulatory agencies in many countries have been slow to accept that the virus can spread by air. It’s a debate that could have implications for the importance of air filtration in reopening businesses and schools.
Dr. Bill Schaffner, an infectious disease specialist at Vanderbilt University, said the new guidance is largely in line with what he says the science indicates about the coronavirus spreading through the air. He said in a phone interview after reviewing the new guidance that airborne transmission is something of a “side street” for spread.
“Some cars do get through on the side street,” he said. “But the highways of transmission are close in, usually within enclosed spaces and for periods of time longer than 15 minutes with people standing within three to six feet of each other.”
Schaffner added that the new guidance doesn’t necessarily change how he thinks about reducing the risk of infection for most people. Wearing a mask, socially distancing and avoiding large indoor gatherings remain the most important steps people can take, he said.
But places of business, where many people come in and out everyday, might want to reexamine their ventilation systems, he said.
“Have your air handling system reviewed and see how efficient it is and whether you’re getting sufficient air exchanges per hour, and where the stuffy corners of the building are,” he said. “See if you can do something to enhance the air handling.”
Abstract Background: Observational evidence suggests that mask wearing mitigates transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is uncertain if this observed association arises through protection of uninfected wearers (protective effect), via reduced transmission from infected mask wearers (source control), or both.
Objective: To assess whether recommending surgical mask use outside the home reduces wearers' risk for SARS-CoV-2 infection in a setting where masks were uncommon and not among recommended public health measures.
Design: Randomized controlled trial (DANMASK-19 [Danish Study to Assess Face Masks for the Protection Against COVID-19 Infection]). (ClinicalTrials.gov: NCT04337541)
Setting: Denmark, April and May 2020.
Participants: Adults spending more than 3 hours per day outside the home without occupational mask use.
Intervention: Encouragement to follow social distancing measures for coronavirus disease 2019, plus either no mask recommendation or a recommendation to wear a mask when outside the home among other persons together with a supply of 50 surgical masks and instructions for proper use.
Measurements: The primary outcome was SARS-CoV-2 infection in the mask wearer at 1 month by antibody testing, polymerase chain reaction (PCR), or hospital diagnosis. The secondary outcome was PCR positivity for other respiratory viruses.
Results: A total of 3030 participants were randomly assigned to the recommendation to wear masks, and 2994 were assigned to control; 4862 completed the study. Infection with SARS-CoV-2 occurred in 42 participants recommended masks (1.8%) and 53 control participants (2.1%). The between-group difference was −0.3 percentage point (95% CI, −1.2 to 0.4 percentage point; P = 0.38) (odds ratio, 0.82 [CI, 0.54 to 1.23]; P = 0.33). Multiple imputation accounting for loss to follow-up yielded similar results. Although the difference observed was not statistically significant, the 95% CIs are compatible with a 46% reduction to a 23% increase in infection.
Limitation: Inconclusive results, missing data, variable adherence, patient-reported findings on home tests, no blinding, and no assessment of whether masks could decrease disease transmission from mask wearers to others.
Conclusion: The recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use. The data were compatible with lesser degrees of self-protection.
Primary Funding Source: The Salling Foundations.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), has infected more than 54 million persons (1, 2). Measures to impede transmission in health care and community settings are essential (3). The virus is transmitted person-to-person, primarily through the mouth, nose, or eyes via respiratory droplets, aerosols, or fomites (4, 5). It can survive on surfaces for up to 72 hours (6), and touching a contaminated surface followed by face touching is another possible route of transmission (7). Face masks are a plausible means to reduce transmission of respiratory viruses by minimizing the risk that respiratory droplets will reach wearers' nasal or oral mucosa. Face masks are also hypothesized to reduce face touching (8, 9), but frequent face and mask touching has been reported among health care personnel (10). Observational evidence supports the efficacy of face masks in health care settings (11, 12) and as source control in patients infected with SARS-CoV-2 or other coronaviruses (13).
An increasing number of localities recommend masks in community settings on the basis of this observational evidence, but recommendations vary and controversy exists (14). The World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (15) strongly recommend that persons with symptoms or known infection wear masks to prevent transmission of SARS-CoV-2 to others (source control) (16). However, WHO acknowledges that we lack evidence that wearing a mask protects healthy persons from SARS-CoV-2 (prevention) (17). A systematic review of observational studies reported that mask use reduced risk for SARS, Middle East respiratory syndrome, and COVID-19 by 66% overall, 70% in health care workers, and 44% in the community (12). However, surgical and cloth masks were grouped in preventive studies, and none of the 3 included non–health care studies related directly to COVID-19. Another systematic review (18) and American College of Physicians recommendations (19) concluded that evidence on mask effectiveness for respiratory infection prevention is stronger in health care than community settings.
Observational evidence suggests that mask wearing mitigates SARS-CoV-2 transmission, but whether this observed association arises because masks protect uninfected wearers (protective effect) or because transmission is reduced from infected mask wearers (source control) is uncertain. Here, we report a randomized controlled trial (20) that assessed whether a recommendation to wear a surgical mask when outside the home among others reduced wearers' risk for SARS-CoV-2 infection in a setting where public health measures were in effect but community mask wearing was uncommon and not recommended.
Methods Trial Design and Oversight DANMASK-19 (Danish Study to Assess Face Masks for the Protection Against COVID-19 Infection) was an investigator-initiated, nationwide, unblinded, randomized controlled trial (ClinicalTrials.gov: NCT04337541). The trial protocol was registered with the Danish Data Protection Agency (P-2020-311) (Part 10 of the Supplement) and published (21). The researchers presented the protocol to the independent regional scientific ethics committee of the Capital Region of Denmark, which did not require ethics approval (H-20023709) in accordance with Danish legislation (Parts 11 and 12 of the Supplement). The trial was done in accordance with the principles of the Declaration of Helsinki.
Participants and Study Period During the study period (3 April to 2 June 2020), Danish authorities did not recommend use of masks in the community and mask use was uncommon (<5%) outside hospitals (22). Recommended public health measures included quarantining persons with SARS-CoV-2 infection, social distancing (including in shops and public transportation, which remained open), limiting the number of persons seen, frequent hand hygiene and cleaning, and limiting visitors to hospitals and nursing homes (23, 24). Cafés and restaurants were closed during the study until 18 May 2020.
Eligible persons were community-dwelling adults aged 18 years or older without current or prior symptoms or diagnosis of COVID-19 who reported being outside the home among others for at least 3 hours per day and who did not wear masks during their daily work. Recruitment involved media advertisements and contacting private companies and public organizations. Interested citizens had internet access to detailed study information and to research staff for questions (Part 3 of the Supplement). At baseline, participants completed a demographic survey and provided consent for researchers to access their national registry data (Parts 4 and 5 of the Supplement). Recruitment occurred from 3 through 24 April 2020. Half of participants were randomly assigned to a group on 12 April and half on 24 April.
Intervention Participants were enrolled and data registered using Research Electronic Data Capture (REDCap) software (25). Eligible participants were randomly assigned 1:1 to the mask or control group using a computer algorithm and were stratified by the 5 regions of Denmark (Supplement Table 1). Participants were notified of allocation by e-mail, and study packages were sent by courier (Part 7 of the Supplement). Participants in the mask group were instructed to wear a mask when outside the home during the next month. They received 50 three-layer, disposable, surgical face masks with ear loops (TYPE II EN 14683 [Abena]; filtration rate, 98%; made in China). Participants in both groups received materials and instructions for antibody testing on receipt and at 1 month. They also received materials and instructions for collecting an oropharyngeal/nasal swab sample for polymerase chain reaction (PCR) testing at 1 month and whenever symptoms compatible with COVID-19 occurred during follow-up. If symptomatic, participants were strongly encouraged to seek medical care. They registered symptoms and results of the antibody test in the online REDCap system. Participants returned the test material by prepaid express courier.
Written instructions and instructional videos guided antibody testing, oropharyngeal/nasal swabbing, and proper use of masks (Part 8 of the Supplement), and a help line was available to participants. In accordance with WHO recommendations for health care settings at that time, participants were instructed to change the mask if outside the home for more than 8 hours. At baseline and in weekly follow-up e-mails, participants in both groups were encouraged to follow current COVID-19 recommendations from the Danish authorities.
Antibody and Viral PCR Testing Participants tested for SARS-CoV-2 IgM and IgG antibodies in whole blood using a point-of-care test (Lateral Flow test [Zhuhai Livzon Diagnostics]) according to the manufacturer's recommendations and as previously described (26). After puncturing a fingertip with a lancet, they withdrew blood into a capillary tube and placed 1 drop of blood followed by 2 drops of saline in the test chamber in each of the 2 test plates (IgM and IgG). Participants reported IgM and IgG results separately as “1 line present” (negative), “2 lines present” (positive), or “I am not sure, or I could not perform the test” (treated as a negative result). Participants were categorized as seropositive if they had developed IgM, IgG, or both. The manufacturer reported that sensitivity was 90.2% and specificity 99.2%. A previously reported internal validation using 651 samples from blood donors before November 2019 and 155 patients with PCR-confirmed SARS-CoV-2 infection estimated a sensitivity of 82.5% (95% CI, 75.3% to 88.4%) and specificity of 99.5% (CI, 98.7% to 99.9%) (26). We (27) and others (28) have reported that oropharyngeal/nasal swab sampling for SARS-CoV-2 by participants, as opposed to health care workers, is clinically useful. Descriptions of RNA extraction, primer and probe used, reverse transcription, preamplification, and microfluidic quantitative PCR are detailed in Part 6 of the Supplement.
Data Collection Participants received 4 follow-up surveys (Parts 4 and 5 of the Supplement) by e-mail to collect information on antibody test results, adherence to recommendations on time spent outside the home among others, development of symptoms, COVID-19 diagnosis based on PCR testing done in public hospitals, and known COVID-19 exposures.
Outcomes The primary outcome was SARS-CoV-2 infection, defined as a positive result on an oropharyngeal/nasal swab test for SARS-CoV-2, development of a positive SARS-CoV-2 antibody test result (IgM or IgG) during the study period, or a hospital-based diagnosis of SARS-CoV-2 infection or COVID-19. Secondary end points included PCR evidence of infection with other respiratory viruses (Supplement Table 2).
Sample Size Calculations The sample size was determined to provide adequate power for assessment of the combined composite primary outcome in the intention-to-treat analysis. Authorities estimated an incidence of SARS-CoV-2 infection of at least 2% during the study period. Assuming that wearing a face mask halves risk for infection, we estimated that a sample of 4636 participants would provide the trial with 80% power at a significance level of 5% (2-sided α level). Anticipating 20% loss to follow-up in this community-based study, we aimed to assign at least 6000 participants.
Statistical Analysis Participants with a positive result on an antibody test at baseline were excluded from the analyses. We calculated CIs of proportions assuming binomial distribution (Clopper–Pearson).
The primary composite outcome (intention-to-treat) was compared between groups using the χ2 test. Odds ratios and confidence limits were calculated using logistic regression. We did a per protocol analysis that included only participants reporting complete or predominant use of face masks as instructed. A conservative sensitivity analysis assumed that participants with a positive result on an antibody test at the end of the study who had not provided antibody test results at study entrance had had a positive result at entrance. To further examine the uncertainty of loss to follow-up, we did (post hoc) 200 imputations using the R package smcfcs, version 1.4.1 (29), to impute missing values of outcome. We included sex, age, type of work, time out of home, and outcome in this calculation.
Prespecified subgroups were compared by logistic regression analysis. In a post hoc analysis, we explored whether there was a subgroup defined by a constellation of participant characteristics for which a recommendation to wear masks seemed to be effective. We included sex, age, type of work, time out of home, and outcome in this calculation.
Two-sided P values less than 0.05 were considered statistically significant. Analyses were done using R, version 3.6.1 (R Foundation).
Role of the Funding Source An unrestricted grant from the Salling Foundations supported the study, and the BESTSELLER Foundation donated the Livzon tests. The funders did not influence study design, conduct, or reporting.