By Dr. Mallika Marshall

BOSTON (CBS) – Now that schools are back in session, many parents are anxious to know when kids under 12 will finally be eligible to get a COVID-19 vaccine. Some experts are saying the decision could come as early as Halloween.

So what is taking so long?

First of all, I think it’s important for parents to know that young children are not just little adults. Their immune systems are often much more robust and responsive than ours. So it’s important for vaccine makers to get the dosing right and make sure enough time is given in clinical trials to identify any safety issues. That can take a few months.

Then, manufacturers have to analyze the data and submit paperwork to the FDA for approval. The FDA takes some time to review the data and make sure the benefits outweigh any risks before giving the go-ahead.

Pfizer says it’s on the brink of filing for approval of their vaccine for children ages 5 to 11, probably in smaller doses than that used in people 12 and up. And while the FDA says it will not cut corners, it will work “around the clock” to make a prompt decision.

If a COVID vaccine is approved by the FDA, the CDC then needs to weigh in and determine how and when to administer it to the public.

All of this takes time, but the agencies are trying to expedite the approval process without compromising its integrity.

Some parents are jumping the gun and asking their pediatricians to go ahead and vaccinate their young children before the vaccines get the green light. This is not a good idea.

Remember, your 5-year-old or 10-year-old may need a smaller dose than a 12-year-old or an adult. So it’s important to wait for the clinical trials to make sure the vaccines are protective in kids, to determine the proper dosing, and to ensure that there aren’t any unexpected safety issues apart from those that have been seen in older kids and adults.

Dr. Mallika Marshall