By Dr. Mallika Marshall

BOSTON (CBS) – Moderna has just petitioned the FDA to authorize its COVID-19 vaccine for use in children ages 6 months to 6 years. There are currently no coronavirus vaccines for kids under 6 in the U.S.

What is the company saying in terms of how effective the vaccine is?

In a clinical trial during the Omicron wave, the company administered the vaccine to children between the ages of 6 months and 5 years old in two separate doses of 25 mcg each, a quarter the dose of the original vaccine for adults. They found the vaccine was 51-percent effective at preventing infection in children under 2 and 37-percent effective in children from 2 to 5 years old. The results were similar to the efficacy in adults during the Omicron surge. They also said there were no safety concerns raised during the trial.

Pfizer had also planned on submitting data on its vaccine for children under 5. Where does that stand?

Right now, Pfizer is the only vaccine authorized for use in kids here in the U.S., namely children 5 to 17. Pfizer had planned to request FDA authorization for its vaccine for children under 5 earlier this year but their two-dose regimen did not produce the desired immune response in this age group, so they are now testing a third dose and hope to submit that data to the FDA in May or June.

It’s unclear whether the FDA is going to consider both companies’ requests separately or wait for Pfizer’s submission so they can determine which vaccine is most effective and offer only one option to parents to avoid confusion.

How big of an impact will this have on families that have been waiting for a shot for the little ones?

As you can imagine, many parents of very young children have been waiting for this for a long time, including my brother out in L.A. who has been afraid to travel with his 14-month-old until she’s vaccinated. But this is just the first stage. The FDA has to review the available data and make recommendations about whether children 5 and under should get this vaccine.

And it’s not a slam dunk because while the Moderna vaccine appears to be about as effective in this young age group as adults against the Omicron variant and while it appears to be safe, experts will have to determine whether the modest benefit is worth any tiny potential risk.

If I had a child under 5, I would be very interested in seeing what the vaccine experts at the FDA and CDC say, but if they do recommend it in the end, I would want my child to have at least some protection because Omicron has been especially hard on children. And hopefully, a vaccine will be authorized before the fall, when kids go back to school and coronavirus cases are likely to climb again.

Do you think most families will be willing to get the shots at this point?

That’s a good question. Only about a third of kids between the ages of 5 and 11 have received at least one dose of the Pfizer vaccine since it became available last fall. Only about 28-percent have gotten both doses. So, if history is any indication, we may not see a greater uptake for kids under 5.

With the possibility of millions more protected, what kind of impact will that have on the pandemic overall?

I’ve heard some people ask whether authorizing a vaccine for kids under 5 will really make a difference since so many kids have been infected during the Omicron surge. But the immunity from vaccination seems to be more robust than that from natural infection. And even if a child has been infected in the past, they could still get infected again. And even though most kids will not get very sick from COVID, some do and others can develop long COVID symptoms, with fatigue and shortness of breath for weeks, and some will go on to develop multisystem inflammatory syndrome which is a serious complication of COVID.

So, if we have a vaccine that is reasonably effective and could potentially protect millions of children around the country, that can have a large public health impact and go a long way to keeping future infections at bay.

Dr. Mallika is offering her best advice, but as always, consult your personal doctor before making any decisions about your personal health. If you have a question, email her or message her on Facebook or Twitter.

Dr. Mallika Marshall