Face masks remain strong defense against virus spread, doctors say

Published on Wednesday, September 1, 2021

By: Karen Bascom

Last year, the University of Mississippi Medical Center advised people to keep their face masks around for a while longer.

With COVID-19 cases and hospitalizations at the highest point in the state since the beginning of the pandemic, masks are more important than ever.

Dr. Bhagyashri Navalkele, medical director for infection control and prevention at UMMC, recommends that people continue to wear masks in public to limit their risk of contracting and spreading COVID-19.

“Masks provide good protection against COVID-19 because they prevent both spread and exposure to the virus,” she said.

Cloth masks work because viruses like SARS-CoV-2 travel through the air suspended in water droplets and aerosols. When worn properly over both nose and mouth, masks create a barrier that decreases the chance of viral particles passing from person to person.

Navalkele says the most effective cloth masks have multiple layers of fabric and do not have vent valves. Disposable medical and surgical masks also provide good protection. In a hospital or clinic setting, Navalkele recommends that health care workers wear N95 masks.

“If you’re seeing COVID-positive patients with high viral loads and the potential for aerosols, this type of mask is going to be most effective,” she said.

In January 2021, the National Academy of Sciences published an evidence review of mask use and COVID-19. It showed that “mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts” and that “public mask wearing is most effective at reducing spread of the virus when compliance is high.” In other words, they found that masks limit the risk of COVID-19 exposure and they work best if everyone wears them.

“Masks are working just as they have been since the beginning of the COVID-19 pandemic,” she said. “However, this new (Delta) variant is more transmissible and masks are still going to provide a good level of protection.”

Navalkele says mask wearing guidance for vaccinated people has changed in the last few months. In May 2021, the Centers for Disease Control and Prevention advised that vaccinated people could do many activities unmasked. However, they based that guidance on the transmissibility of earlier SARS-CoV-2 variants.

“We were in a position at the time of decline in cases and rapidly increasing vaccinations,” said Dr. Paul Byers, chief epidemiologist for the Mississippi State Department of Health and faculty member at the UMMC John D. Bower School of Population Health, said in a July 28 news conference. “With the Delta variant, it’s time for us to consider some additional public health recommendations.”

Byers said the MSDH updated their mask guidance to align with the CDC “in order for the public to be aware of what the risks are and what the updated public health guidance is now in order to protect themselves and their family and limit transmission in Mississippi.”

With the Delta variant, “We have seen that even fully vaccinated people can have breakthrough infections. They are less common and less likely to transmit the virus compared to unvaccinated people, but they can still spread the infection to others,” Navalkele said.

With this in mind, she recommends that all people age 2 or older, regardless of vaccination status, wear masks in indoor spaces outside their homes. That includes grocery stores, restaurants, public transportation, hospitals – anywhere. Navalkele also says people should wear masks at crowded and close contact outdoor events, such as concerts or festivals.

If you or someone in your household has a confirmed COVID-19 diagnosis, wearing a mask at home can help prevent you and the people you live with from spreading or contracting the virus.

Vaccinated and unvaccinated people participating in outdoor activities where you can keep a distance from others do not need to wear masks, Navalkele said.

This mirrors the current CDC guidance that vaccinated people wear masks when they are indoors in public if they are in a county that has high or substantial level of community transmission of COVID-19. As of August 26, every county in Mississippi is in the high category.

Navalkele said that consistent mask wearing could have other public health benefits as well.

“During the last flu season we had hardly any cases. Because of mask mandates, we were able to avoid a surge in influenza cases in addition to COVID-19,” she said.

She says that if not enough people wear masks, “we are likely to see more influenza than last year.”

There are already some signs that lax regulations and behaviors could drive out-of-season disease surges, such as the recent increase in respiratory syncytial virus (RSV) cases at Children’s of Mississippi and across the Southeast.

While masks are an effective way to prevent the spread of COVID-19 and other respiratory viruses, they work even better when used with another preventive measure.

“Please get vaccinated,” Navalkele said, “and do it as soon as you can,” because it takes about two weeks for full immunity to kick in.

“The vaccine doesn’t work in one second. It doesn’t work in one day,” she said. “You need to take the full dose to be fully vaccinated.”

For COVID-19, that means two doses of either the Pfizer or Moderna vaccines, or one dose of the Johnson and Johnson vaccine. The first is approved by the Food and Drug Administration for people ages 16 and older and has an emergency use authorization for children aged 12 to 15. The others have a EUA for adults age 18 and older. In addition, she recommends encourage people to receive a flu shot.

If you are looking for the most up-to-date guidance on masks, vaccines and other public health issues Navalkele recommends reliable sources such as the CDC and Mississippi State Department of Health websites.

“This information comes from experts in the field, and it’s where I go when I want to check the most recent guidance,” she said.

The above article appears in CONSULT, UMMC’s monthly e-newsletter sharing news about cutting-edge clinical and health science education advances and innovative biomedical research at the Medical Center and giving you tips and suggestions on how you and the people you love can live a healthier life. Click here and enter your email address to receive CONSULT free of charge. You may cancel at any time.