Brandon Brown. Credit: UCR/Stan Lim

Are you double masking on some occasions the way Pete Buttigieg, President Joe Biden's Secretary of Transportation, and Amanda Gorman, the youngest inaugural poet in U.S. history, have? Does double masking have real benefits? How often should we change our masks?

Epidemiologist Brandon Brown at the University of California, Riverside, answers these and other common questions related to masks in a Q&A. Brown is an associate professor in the School of Medicine's Department of Social Medicine, Population, and Public Health.

Should we physically distance and wear a mask even after we get vaccinated?

Definitely. Getting two doses of the vaccine will likely protect us from getting sick, but we can still potentially spread the virus to others. So, we need to continue to physically distance and wear masks until we have achieved herd immunity with vaccination.

After vaccination, are you wearing a mask to protect others more than yourself?

Yes. Masks are a way to protect others from the virus, not just ourselves. We should also remember that while vaccines are highly effective, they are just one tool in our COVID-19 prevention toolkit, and we all need to do our part to protect ourselves and others as much as possible.

When would it be time for all of us to take off our masks? What indicators would dictate this decision?

In some countries it is quite normal for people to be wearing a mask in public even in pre-COVID times. This pandemic has brought forth a heightened awareness of airborne viral transmission, which is definitely a good thing. Once we have achieved , it would be safe to remove our masks, but a certain portion of the population may want to continue wearing masks at times such as in flu season when in public spaces.

Double masking has become a practice among some, particularly when in tight quarters indoors—such as on flights. How does that help, if it does?

Double masking has recently been validated by Dr. Anthony Fauci, in that doubling up on cloth masks can help filter more particles than a single cloth mask alone. No matter how many masks, you want to make sure that masks cover both your nose and mouth fully. And it helps to have a filter to the inner layer of the mask. Not all masks are created equal, so it helps to double up on cloth or other face coverings to ensure maximum protection from transmission. There is a new mandate to wear masks during public transportation which should assist in stopping the spread.

Is double masking necessary if you're wearing an N95 mask?

An N95 is the gold standard and it can seal to the face and filter 95% of particles. So, no doubling up required.

How often should a mask be replaced?

It depends on the mask, and you get what you pay for. Some cloth masks are machine washable, but you can also wash them by hand. Hold up your mask and look for any holes or areas where you can see through, and if that's the case you should throw it out and put on a new one. Cloth masks with more fabric layers are better than single-layer .

How should a mask be stored in between uses?

Never put your mask in your pocket and don't touch the front of your mask. Use the strings on the side to put on and remove the mask and wash your hands after you remove it. Once removed, store your mask in a paper bag or somewhere else that is not on a frequently touched surface.

Now that outdoor dining is being permitted in California, what are your tips for dining safely?

Many restaurants have created outdoor dining that is similar to indoors, with temporary walls to enclose the space on all sides. While it keeps us warm, this is similar to indoor dining and not best for avoiding transmission. You want to make sure you have good air circulation when outdoor dining, good physical distancing from other customers outside of your household, and also adequate distancing from others who may be walking outside without a mask.