Twin 9-year-old girls become first in country to take part in Pfizer's Pediatric Vaccine Trial at Duke

DURHAM, N.C. (WTVD) -- Twin 9-year-old girls became the first in the United States to participate in Phase 1 of the Pfizer and BioNTech Clinical Study Trial in children younger than 12.

"For any person enrolling in a study, and in this case as a parent asking your children to do that, you have to acknowledge that you're assuming some risk," said Dr. Susanna Naggie, the mother of Alejandra and Marisol Gerardo.

Dr. Naggie is also an associate professor of infectious diseases at Duke University's School of Medicine, and along with her husband, who is also a healthcare provider, has been fully vaccinated with the Pfizer version.

"My spouse and I both agreed that it was a pretty low-risk situation because we have confidence in the safety of the vaccine, of the process, and then particularly as you said we've been vaccinated with the same vaccine, that does give you a level of comfort," said Dr. Naggie.

Dr. Naggie and her husband explained the vaccine trial and asked their girls if they felt comfortable participating.

"They were both quite keen to be a part of this. I think they were excited to tell their friends at school, and maybe might be able to say they're the first ones at school to get it," Naggie said.

Alejandra and Marisol got their shots Wednesday.

"Certainly last night, they woke up with sore arms, which they both thought was a really good sign, it must mean it's working, they said. So other than that, they looked great this morning, and actually made soccer practice last night," Naggie said.

Pfizer's pediatric trial is broken down into three phases. Phase 1 evaluates three different dosage levels, with 16 healthy children assigned to receive varying amounts of two doses, 21 days apart.

Data from that group of 48 children will help guide the next two phases of the study, which evaluates the safety, tolerability, and protection provided in different age groups.

"They're not just little adults. They're a little bit different. So it's really important that we kind of assess what the side effects are from the vaccine," said Dr. Emmanuel Walter, the Chief Medical Officer of the Duke Human Vaccine Institute.

Thursday, Gov. Roy Cooper announced expedited plans to expand eligibility in hopes of reaching more people and increasing vaccination rates. Though the focus is on people 16 years and older, down the line that will shift to people of all ages.

"It's important to achieve herd immunity or community protection from infection. And in order to do that, you need to vaccinate a significant proportion of the population, probably 70 to 80 percent of the population, while children make up a significant proportion of our population. So in trying to achieve herd immunity, it really is important that we are able to include children in vaccination programs," Walter said.

The Pfizer vaccine is authorized for people 16 and older, while the Moderna and Johnson & Johnson vaccines are authorized for those 18 and older.