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.

Nancy writes, “My husband and I had two doses of Pfizer in March and recently had breakthrough cases of COVID earlier this month. Is it still recommended that we get a booster and, if so, how long should we wait before we do?”

It’s hard for me to give you a clear answer because we just don’t know for sure yet. If you’re fully vaccinated and then get a breakthrough infection, you’ve gotten a natural boost in your immunity, so there probably is no need to rush out and get a booster shot now. But depending on your age and your underlying health, you may need a booster down the road. I would discuss this with your personal physician.

Milani says, “I am scheduled to have my Moderna Booster shot and plan to travel. What are the chances of having a false-positive given the fact that I would have had the vaccine five days earlier?”

The COVID-19 vaccines and boosters will not cause you to test positive for the virus. If you test positive with a PCR test, you are infected with the coronavirus.

Sandy writes, “I received Pfizer almost six months ago. With all the talk about Pfizer becoming less effective over time faster than Moderna, should I wait and get a Moderna booster?”

Studies have suggested that you might get a little extra bump in antibodies with the Moderna booster compared to the Pfizer booster, but I don’t think you can go wrong with either. I had Pfizer for my first two doses and got Pfizer for my booster. But I would have been equally happy to get a Moderna booster had it been available at the time.

Dana writes, “My husband and I are fully vaccinated. We’re due for boosters in November and December, respectively. How protected are we from Covid and how long will the Booster last? And are the side effects similar to the 1st or 2nd shot?”

We don’t know how long the boosters will last, but there is hope that they will extend immunity longer than the original vaccine series. Even before you get a booster, you should still be well protected from hospitalization and death, but it would be nice to get a little bump in your antibodies since we know immunity does wane with time. The side effects of the boosters tend to be similar to the original vaccines.

Dr. Mallika Marshall