The rapidly increasing number of coronavirus cases and breakneck pace of the omicron variant as it spreads across the nation have prompted health experts to reemphasize the importance of wearing masks to help slow the spread of the disease and protect the vulnerable. Some states have reinstated mask mandates in indoor public spaces in response to rising case counts.

Public health agencies continue to highlight vaccination, including booster shots for people who are eligible, as the first line of defense against the omicron variant. Meanwhile, some experts are also recommending that people not only resume wearing masks, but that they also consider upgrading cloth masks to surgical masks, and, in certain cases, respirators, even if they are vaccinated.

The Centers for Disease Control and Prevention recently updated its guidance on masks, noting that N95 respirators offer the most protection against omicron while “loosely woven cloth products” offer the least. Additionally, President Biden announced on Jan. 13 that free, high-quality face masks would be made available to all Americans.

“It’s time in many places in the country that we mask up again,” said Jaimie Meyer, an infectious-disease physician at the Yale School of Medicine. “We need those extra layers of protection that we didn’t necessarily need as much a couple months ago, when levels of virus that were circulating were relatively low.”

William Schaffner, medical director of the National Foundation for Infectious Diseases, agreed: “Given the contagiousness of this virus, I think we should get that mask back out of our drawer and put it on, particularly when we’re going indoors to group activities where there are congregations of people.”

Some people are catching coronavirus after being vaccinated. Johns Hopkins University infectious disease expert Lisa Maragakis gives advice on how to stay safe. (John Farrell/The Washington Post)

Below we’ve compiled answers to some of the most commonly asked questions about masks and how to use them in this latest phase of pandemic life. These recommendations are drawn from guidance from the Centers for Disease Control and Prevention, previously published Washington Post articles and new interviews with experts specializing in infectious diseases, public health and air quality.

Please keep in mind that as the coronavirus, its variants and vaccines continue to be studied and understood, masking advice is likely to change.