By Dr. Mallika Marshall

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.

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Barbara writes, “A lot of us are not getting the vaccine because we still have to wear masks and such. Tell me I can go to an indoor concert without a mask, and I will be happy to get the vaccine.” 

As you have probably heard, the CDC has loosened guidelines about wearing masks outdoors if you’re fully vaccinated. So you can walk your dog, go to an outdoor restaurant, have a small backyard gathering with other vaccinated people. Yes, if you’re outdoors in a crowd or in close proximity with others who are not vaccinated, you still need to wear your masks. But I think we’ll get to the point where those who are vaccinated can safely be indoors without having to wear masks.

Tracy asks, “I learned that a close contact tested positive for COVID. I got tested last night and my results were negative. I am supposed to receive my 2nd Pfizer dose in just a few days. Do I need to reschedule my 2nd shot?”

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If you’ve been exposed to COVID-19, you should probably postpone your vaccine until you have completed your 14-day period of quarantine. This is a precaution so that you don’t put others at risk. Even if you need to delay your 2nd dose by a week or two, you should still mount a good immune response.

Cindy asked on Facebook, “Because of the reported side effects of the J&J vaccine, why don’t they just give that one to men only and offer women one of the other choices?”

Some countries are limiting the use of the J&J vaccine to people over 60 since the rare blood clots have been seen in younger adults, mostly women. The J&J vaccine now has a warning label but no specific age or gender restriction here in the U.S. I think it’s reasonable for women under 50, however, to get the Pfizer or Moderna vaccine instead, especially since those vaccines are more readily available now.

Sarah writes, “If a person got the first dose of the AstraZeneca vaccine in India in March, could he take either Pfizer or Moderna as the second dose? He is here in the U.S. now.”

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UK scientists are studying this right now, but in the meantime, many health experts think, while not ideal, mixing and matching COVID vaccines is probably safe. Here in the U.S., we don’t offer the AstraZeneca vaccine so his only options would be the Pfizer, Moderna, or J&J vaccines.

Dr. Mallika Marshall