As COVID continues to rapidly spread through the country especially now with omicron in the picture it might be time to upgrade your face mask strategy. In early 2021, health experts recommended double masking , a move that may be useful again.

A study published by the Centers for Disease Control in February found that wearing two masks is more effective at preventing coronavirus transmission than one. The research suggests that wearing one medical grade mask such as a surgical mask underneath a cloth mask significantly boosts protection against SARS-CoV-2, the virus that causes COVID-19.

Experts also say new variants are thought to have an easier time binding to our cells, so the more layers we have covering our noses and mouths, the less likely well be exposed to viral particles that can infect our cells and make us sick. Two masks may help create a stronger shield between you and the virus (or, at the very least, they couldnt hurt).

Heres everything you should know about double-masking including how to go about it so you can prevent COVID-19 as best as you can:

Pick two masks that have enough layers and air filtration.

The more layers, the more barriers you can put between yourself and the virus, the better off youre going to be, said Thomas Duszynski , the director of epidemiology education at Indiana Universitys Richard M. Fairbanks School of Public Health.

N95 face masks are the gold standard in terms of protection. If you can get ahold of an N95 and double it up with a surgical mask, youre going to have an efficient shield against viral particles.

But N95 masks continue to be in limited supply, so theyll be difficult to score for the time being. The issue then is how to spice up your cloth or surgical face masks, said Onyema Ogbuagu , a Yale Medicine infectious disease doctor and principal investigator of Yales Pfizer COVID-19 trial.

The two properties of a mask you want to look for are the filtering capacity and the breathability, according to Ogbuagu. You want masks that can both filter the air we breathe in and limit how many respiratory secretions we shoot out.

KN95 masks are thought to be pretty good alternatives to N95 masks in non-clinical settings. They might not be quite as rigorous as N95s theres really no beating them but KN95 masks still offer a lot of protection for you and others when sealed around your nose and mouth. (Heres a list of the KN95s that have received emergency use authorization.)

Surgical masks are great for protecting you and others against large respiratory droplets, but due to their loose fit, theyre not foolproof at keeping out all of the smaller, aerosolized particles. (Tip: if your surgical mask is loose, try tying knots in the ear loops to keep it taut.)