BOSTON (CBS) —  Dr. Mallika Marshall is answering your coronavirus vaccine-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.

Both Jim in Newton and Penny both want to know, “How do KF94 masks compare to KN95 masks? Is one better than the other?”

KF94 masks are made in South Korea and KN95 masks are made in China. Both are designed to replicate the N95 masks and provide better protection than surgical masks and certainly cloth masks. And while KF94s and KN95s have some minor differences in style, they are pretty equivalent in their ability to filter. Whichever one you choose, make sure they aren’t knock-offs and that you’re able to get a good seal.

You can consult the following website for more information:

Both Kathy and Carol ask, “Can you get a rash from COVID-19?”

Yes, you can get rashes from COVID-19, including hives, itchy bumps, even blisters. So if you have other symptoms consistent with COVID or were exposed, you should get tested. But there are other causes of rashes as well. For example, is there anything else you have used recently that could trigger a rash, like new creams, cosmetics, detergents, foods, or new medications? If the rash is not improving, you should see a doctor.

Debbie asks, “Why don’t COVID vaccine antibodies don’t last as long as other vaccines like the measles?”

We don’t actually know how long immunity lasts from the vaccines or natural infection, but the coronavirus has been mutating fairly rapidly, allowing the virus to escape some of our defenses. But while people who are vaccinated are experiencing higher rates of infection with the Omicron variant than with prior variants, the vaccines are still extremely effective at preventing severe disease, hospitalization, and death.

And Paula writes, “I am a senior citizen who lives alone and has no family. How do I care for my dog without anyone to help me if I get Covid? I cannot isolate myself from him.”

The CDC does caution people not to have close contact with their pets while infected, but Paula, please don’t worry about your dog. Animals can get COVID from humans, but it’s incredibly rare and you’re unlikely to transmit the virus to your pet if you take simple precautions. Keep some distance between you and your dog, like avoiding kissing the dog or sleeping on the same bed. If you don’t have a fenced-in yard, you might consider hiring someone to walk the dog or use wee-wee pads in your home. But please, don’t worry about caring for your pet if you’re home with COVID.

Dr. Mallika Marshall