By Anna Meiler

CAMBRIDGE (CBS) – Pfizer said Wednesday that its COVID-19 vaccine is 100-percent effective in children ages 12 to 15.

Right now their two-shot vaccine is approved for people 16 and older. But, the company now hopes to expand that to ages 12 and up after preliminary results from this small study.

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Pfizer said 2,260 children ages 12 to 15 took part in the phase three trial. The company said preliminary data shows 18 cases of COVID-19 in the placebo group and zero cases in the vaccinated group.

“We plan to submit these data to FDA as a proposed amendment to our Emergency Use Authorization in the coming weeks and to other regulators around the world, with the hope of starting to vaccinate this age group before the start of the next school year,” Pfizer CEO Albert Bourla said in a statement Wednesday.

“We knew Pfizer did very well starting at age of 16 and now they’re telling us the response is even better in children 12 to 16 which I think is excellent news,” Dr. Rick Malley, a physician in the Division of Infectious Diseases at Boston Children’s Hospital, told WBZ-TV.

He is eager to see the specifics of the study, but he says Wednesday’s announcement is exciting.

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“The company is stating they did not have any concerns over the tolerability or the safety of this vaccine and that is great news.”

Twelve-year-old Caleb Chung said he decided to take part in Pfizer’s clinical trial to help make a difference in the pandemic.

“Usually I’m just at home doing online school and there’s not much I can do to fight back against the virus so participating in this trial and potentially helping other kids to feel safe and want to get the vaccine in the future when it becomes publicly available was really some way that I could actually help out,” he said.

Pfizer also provided an update on their trials for children. Kids 5 to 11 years old started receiving coronavirus vaccines last week and the company plans to start administering doses to children ages 2 to 5 next week.

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Cambridge-based Moderna also hopes to lower the age limit for its COVID-19 vaccine. Earlier this month it started a study on children under the age of 12.

Anna Meiler