HOPKINTON, Mass. - Hopkinton High School is the first school in Massachusetts to get state approval to drop the in-school mask mandate and a local pediatrician is weighing in on the decision.

In order to meet the state's threshold for removing masks, at least 80% of all students and staff at the school have to be vaccinated.

UMass Memorial Children's Medical Center pediatrician, Dr. Christina Hermos, says approaching herd immunity, where enough people are vaccinated that there won't be sustained transmission in the community or school, has been the goal since the vaccine was approved.

She says its difficult to pinpoint an exact percentage, because the COVID vaccine is not 100% effective and it's not just the number of children vaccinated, but also the numbers of children who are truly protected at any given time.

"I think Hopkinton is doing what we said we would do and cautiously making masks optional for vaccinated students and staff," Dr. Hermos said. "Which I think is reasonable with a lot of monitoring."

When it comes to the vaccine itself, Dr. Hermos says it is incredibly safe and effective. She says she recommends children as young as 5 years old receive it if the FDA grants it emergency use approval.