By Dr. Mallika Marshall

BOSTON (CBS) – Dr. Mallika Marshall is answering your coronavirus and coronavirus vaccine-related medical questions. If you have a question for Dr. Mallika, 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.

“My granddaughter is 11 but by size, she looks more like a 13 or 14-year-old.  She will not be 12 until February. Would you recommend we wait until February so she can get the full dose of the vaccine for better protection?” – Paula on Facebook

Vaccines are not dosed the same as medications like Tylenol or antibiotics which are based on weight.  Vaccines use a minuscule amount of material deposited into the arm (or thighs in babies) to stimulate an immune response.  The dose is largely determined by the robustness or responsiveness of the person’s immune system.  Children tend to have more robust immune systems than adults.  I would hate for your granddaughter to get infected while waiting for her 12th birthday so you should consider getting her vaccinated as soon as she is eligible.

Both my 9-year-old and 11-year-old weigh in above 100 pounds. Why would they get a lower dose than an adult? – Jessi

Vaccines are not dosed the same as medications like Tylenol or antibiotics which are based on weight.  Vaccines use a miniscule amount of material deposited into the arm (or thighs in babies) to stimulate an immune response.  The dose is largely determined by the robustness or responsiveness of the person’s immune system.  Children tend to have more robust immune systems than adults.

“Are the side effects the same for 5 to 11-year-olds as they are for adults?” – Alexis

Yes.  The company says they saw similar side effects in this age group compared to 16 to 25-year-olds but the younger kids, at these lower doses, may have had even less fever, chills, body aches, and other symptoms.  We’ll have to see all of the data to be sure.

“My grandson, age 11, had COVID over the summer. should he get the vaccine as soon as it is available? Does he have some immunity right now?” – A “Massachusetts Grammy” 

If your grandson had COVID-19, yes, he has probably built up some immunity to the coronavirus, but we don’t know how long that immunity will last.  It is generally recommended that people who have had COVID get vaccinated within 3 months of their infection.  So by the time the vaccine becomes available for kids ages 5 to 11, your grandson should probably get the shots.  But please double-check with his pediatrician.

“I have a 7-month-old and can’t wait to get her vaccinated.  When can she finally get her shots?” – Marcy

Pfizer expects to have preliminary data available on kids ages 2 to 5 in the next month and then kids 6 months to 2 years soon after that.  Moderna is also studying its vaccine in kids as young as 6 months.  But authorization for use in kids this young probably won’t happen until the end of this year, beginning of next.

Dr. Mallika Marshall