WebMD News Brief

Face Shields May Be Next Step to Prevent COVID

photo of face shield

May 29, 2020 -- Face masks have become commonplace in the effort to combat COVID-19, but some doctors say it is time to take protection a step further and try full face shields as restrictions slowly begin to loosen.

Face shields are nothing new in medical settings -- doctors and nurses who treat coronavirus patients are using them along with standard face masks. Health care professionals are split on whether they should also be worn by children, teachers, and in offices while states reopen.

“Face shields appear to have a number of advantages: They’re easy to wear correctly and good at blocking droplets,” says Eli Perencevich, MD, an infectious disease doctor at the University of Iowa and the Iowa City Veterans Affairs Health Care System. “They’re really a better option for protection.”

Perencevich and his colleagues published a report in JAMA last month, arguing that face shields have more COVID-fighting potential than standard masks when used with increased testing, contact tracing, and social distancing.

A few things make shields superior, he says. For one, many people wear masks that don’t fit well, so they don’t work as well. They also prompt people to touch their faces more, increasing the risk of viral spread. They leave much to be desired in terms of comfort, he says, and they make it harder to breathe.

Shields come with the perk of being easily sanitized and reused, says Keith Kaye, MD, a professor of medicine and director of research for the division of infectious diseases at the University of Michigan Medical School.

Unlike masks, clear shields also allow for better communication -- people can read facial expressions, and those who are hearing impaired can read lips, he says.

“I do think we're going to see more and more face shield use,” Kaye says. “Particularly as COVID continues to cause problems.”

While there is not a lot of data on how well masks work, one recent study in China found that wearing a mask at home reduced transmission to other members of the same household by nearly 80%.

Shields, meanwhile, have been found to successfully block droplets. One cough simulation study in 2014 found that a shield may reduce exposure by 96% when worn within 18 inches of someone coughing.

In addition, face masks are not meant to protect the wearer -- they leave other vulnerable parts of the face exposed, like the eyes. They are meant to keep an asymptomatic or pre-symptomatic person from spreading it to others.

But not all doctors are sold on everyday use of more extreme protective gear. Dan Kuritzkes, MD, chief of infectious diseases at Brigham and Women’s Hospital in Boston, says the eye coverage that shields provide is likely not necessary for people unless they are providing medical care to COVID-19 patients.

“In theory, it may be possible that particles could land in someone’s eye and cause infection, but we don’t have good evidence that happens,” he says. “I think the bottom line is for the general public, there's no reason to be wearing face shields.”

He also says they may not help prevent airborne transmission, because air that has droplets in it could get sucked under the shield from the bottom opening.

Face shields are important in health care settings because, in those situations, mucous membranes around the caregivers’ eyes that could come into contact with harmful droplets while they do procedures like intubation, says Timothy Brewer, MD, a professor of medicine and epidemiology at the UCLA Fielding School of Public Health and Medicine.

As long as everyone abides by recommendations to wear a face mask, that risk won’t exist for non-health care workers.

“It could potentially get in someone’s eyes if someone sneezes -- that's why the person sneezing should also be wearing a mask,” Brewer says.

Meanwhile, other parts of the world are embracing the use of face shields outside of hospitals. School children in Singapore are being given face shields as they head back to classes in the coming days.

The Infectious Diseases Society of America has listed widespread use of protective gear, including face shields, in the process of lifting restrictions, but the CDC still recommends just face masks for people outside the health care realm.

Still, people and companies have jumped in to help supply shields to both health care workers and other people at higher risk of catching the virus.

Amazon announced this month that its engineers are developing face shields to sell on its site after donating almost 10,000 to people on the front lines.

Other efforts have come from everyday citizens. Katherine Marcano-Bell and her family have converted part of their 1,300-acre pig farm into a shield-making operation, and have delivered them to hospitals, clinics, meatpacking plants, and families who have made specific requests for them.

“I think it wouldn't hurt to wear one, especially if you're sick or immunocompromised,” Marcano-Bell says.

WebMD Health News Brief Reviewed by Brunilda Nazario, MD on May 29, 2020

Sources

CDC: “About Cloth Face Coverings.”

CNBC.

The Journal of the American Medical Association: “Moving Personal Protective Equipment Into the Community: Face Shields and Containment of COVID-19.”

The Infectious Diseases Society of America: “Policy and Public Health Recommendations for Easing COVID-19 Distancing Restrictions.”

Journal of Occupational and Environmental Hygiene: “Efficacy of Face Shields Against Cough Aerosol Droplets From a Cough Simulator.”

Katherine Marcano-Bell.

Keith Kaye, MD, professor of medicine and director of research, division of infectious diseases, University of Michigan Medical School.

Eli Perencevich, MD, infectious disease doctor, University of Iowa and the Iowa City Veterans Affairs Health Care System.

Dan Kuritzkes, MD, chief of infectious diseases, Brigham and Women’s Hospital, Boston.

Timothy Brewer, MD, professor of medicine and epidemiology, UCLA Fielding School of Public Health and Medicine.

Channel News Asia: “COVID-19: Pre-school and primary school students to get face shields, hand sanitiser.”

BMJ: “Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China?"

© 2020 WebMD, LLC. All rights reserved.