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.

READ MORE: Mother, Man Arrested In Investigation Into Missing New Hampshire 5-Year-Old Elijah Lewis

Cindy wants to know, “What is the wait time between the flu shot and a booster?”

The CDC says you no longer need to wait any time between getting a COVID-19 vaccine and any other vaccines, including the flu shot. You can get them on the same day.

JoAnn writes, “I understand people with underlying conditions can receive a Pfizer booster. What are those underlying conditions?”

READ MORE: 'My Daughter Doesn't Feel Safe': Parents, Teachers Raise Concerns About Violence At Lawrence High School

Examples include cancer, chronic lung disease, kidney disease, diabetes, heart disease, pregnancy, and obesity but there are others. You check the CDC website for the full list.

Dianna wonders, “If both parents test positive for COVID-19 and their child under 2 tests negative, is it advisable to take the child to the grandparents or great grandparents’ home until the parents recover?”

There is a chance the child could test positive up to 14 days after exposure so if there is concern that a grandparent and certainly a great grandparent could get infected and seriously ill, it’s probably better to keep the child with his or her parents. The toddler is unlikely to get really sick even if he or she gets infected, whereas someone who is older could get sick even if they are vaccinated.

Ron is 81-years-old and has diabetes. He says he got vaccinated in the spring but came down with COVID-19 last month. He wants to know if he still needs to get a booster shot.

MORE NEWS: How Colin Powell Made An Impact In Massachusetts

Thank goodness you’re okay and chances are you’re okay because you got vaccinated before getting infected. You probably developed some immunity after having COVID but it’s unclear how long that immunity will last and given your age and your underlying diabetes, you would still be at risk if you got it again. Therefore you probably should get a booster at some point but you may be able to wait a little while. I would talk to your primary care doctor about the timing.

Dr. Mallika Marshall