COVID-19 vaccines could soon be approved for some children under the age of 16, and two teenage siblings from Massachusetts took part in those trials.Zoe Campbell, 15, and Esme Campbell, 13, participated in Cambridge-based Moderna's child COVID-19 vaccine trials back in March, and Esme was just 12 when she participated."I thought it would be really cool if I could be one of the people contributing to making the vaccine available for kids," Esme Campbell said."I was just really excited because with the pandemic, a lot has felt out of my control, and I've been looking forward to the vaccine for about a year now," Zoe Campbell said.The girls' father, Dr. Justin Campbell of South Shore Health, says he and his wife, Dr. Lucy Chie of Beth Israel Deaconess Medical Center, did their research on the COVID-19 vaccine and that they all made a decision as a family."We didn't want to force our kids into doing it," Dr. Campbell said. "We did feel like it was very likely safe."The Pfizer COVID-19 vaccine is the only one that is approved for children as young as 16, but a decision on extending emergency use authorization to children as young as 12 could come soon.Dr. Rick Malley, a senior pediatric physician within Boston Children's Hospital's Division of Infectious Diseases, says families should know the COVID-19 vaccines are being thoroughly evaluated."We're very hopeful that (the decision) should be in the next few weeks," Malley said. "If the time comes for these vaccines to be authorized for teenagers as early as 12 or 13 years of age, it should be felt that these vaccines have gone through a very thorough process."Dr. Campbell says his children experienced mild symptoms after receiving their second dose of the COVID-19 vaccine. He likens what Zoe and Esme are doing to the polio vaccine trials."Polio also had to be trialed on children, and the service that all those families and those kids did for the world was incredible," he said.Children will be able to be vaccinated against COVID-19 by the fall if emergency use authorization is approved soon.Massachusetts vaccination progress