BOSTON (CBS) — Dr. Mallika Marshall is answering your coronavirus-related medical questions. If you have a question, email her or message her on Facebook or Twitter.

Dr. Mallika is offering her best advice, but as always, consult your personal doctor before making any decisions about your personal health.

Martha from Marlborough writes, “My husband and I are in our early 70s, fully vaccinated and boosted. We wear our masks while working out in the gym but is it safe to continue to use the pool and do water aerobics which helps with joint pain?”

Honestly, I would avoid being anywhere indoors without a good quality mask these days. Not until we get over this Omicron hump. I’m not sure you can do water aerobics with a medical mask in place, so maybe you can put things on hold for a few weeks until the Omicron cloud passes.

Linda asks, “Does a patient develop an immunity after having COVID?”

If you test positive for COVID, you will likely develop some degree of immunity, unless you are immunocompromised. However, we don’t know how long that immunity lasts which is why it is still important to get vaccinated and boosted when eligible.

Anonymous writes, “We’re starting to see new guidance on masks saying cloth may not be the best choice or that we should be double-masked. What is acceptable?”

Omicron is so contagious that it is now recommended to ditch cloth face masks that are porous and instead wear a disposable 3-ply medical-grade mask. If you’re in close proximity indoors with others and if you’re at high risk, you may want to use two medical masks or wear an N95 or KN95 mask which have even more layers, provide a tighter seal, and are more readily available now.

Kathy says, “I have recently heard of people getting rapid nasal swabs that turn out negative but when they swab their throat they’re positive! Should we be swabbing our throats instead?”

The long nasal PCR swabs provide the most reliable results. Throat swabs are acceptable alternatives for PCR testing but may not be as sensitive. Rapid tests, which usually involve short cotton swabs in the nose, are less reliable than PCR tests. Perhaps the people you’re hearing about did a rapid nasal swab but then followed it up with a PCR throat swab which was able to detect the virus early on when the rapid nasal swab could not.

Dr. Mallika Marshall