(CNN) Now that the United States has rolled out Covid-19 booster shots for all fully vaccinated adults, some parents have been wondering if or when their vaccinated teenagers might need to get a booster dose of vaccine -- and researchers are working to have an answer soon.
Currently, a booster dose of the Pfizer/BioNTech or Moderna coronavirus vaccines are recommended for all adults who completed the original two-dose series of those shots at least six months ago, and a booster dose of the Johnson & Johnson vaccine is recommended for adults who completed a single shot at least two months ago.
It was about six months ago -- in May -- when the US Food and Drug Administration authorized the emergency use of Pfizer's coronavirus vaccine for adolescents ages 12 to 15, and the US Centers for Disease Control and Prevention recommended the vaccine for this age group. Shots started going into arms shortly thereafter.
"We don't know yet if children will need boosters. But we are actively working on the study to answer that question," said Dr. Flor Munoz, a pediatric infectious disease specialist at Texas Children's Hospital, one of the sites in Pfizer's pediatric vaccine trials.
Munoz wrote in a text message to CNN on Thursday that "it is part of the study design to follow children at various time points after receiving two doses of vaccine."
The pediatric studies are underway and "data should be available next year," Munoz added.
Adolescents might need boosters at some point, but "it is less likely that they will, because your healthy, strapping teenagers have a much better and stronger immune response than I do as an elderly person. I gulp when I say elderly but that is the truth," Dr. Anthony Fauci, director of the National Institutes of Allergy and Infectious Diseases, told CNN's John Berman on Wednesday.
Coronavirus vaccines help the body to develop protection, or immunity, against the coronavirus that causes Covid-19. That immunity can wane over time, but a booster dose of vaccine helps to build that immunity back up.
For adults, Fauci strongly encourages anyone 18 and older who has been fully vaccinated with the original regimen to get a booster shot because of the waning immunity.
When it comes to immunity in adolescents, "it may be that they will go a much longer period of time before they start to wane," Fauci said. "They have a very robust immune system. So I would not be surprised that they will have a protection that will go way out beyond that six months."
While there have been several recent studies documenting the waning immunity observed in fully vaccinated adults, there has not been much data on immunity in vaccinated adolescents over time. Having that data -- specifically weighing the safety and benefits of boosters for this age group -- can be helpful when considering if adolescents might need booster doses at all.
"We don't have enough data yet specifically on the adolescent population to recommend boosters for all adolescents," Dr. Saju Mathew, an Atlanta-based primary care physician and public health specialist, told CNN on Thursday.
"At this point, I am not likely to personally recommend that my adolescent population get a booster shot," Mathew said, since there is that lack of data -- paired with how children are at a lower risk of severe Covid-19 than adults -- and the mRNA coronavirus vaccines, Pfizer and Moderna, come with a small risk of heart inflammation in young people.
"However, I do have some adolescents with underlying medical conditions," Mathew added.
"So, if a 17-year -old has severe asthma, maybe cystic fibrosis, or some kind of underlying pulmonary condition especially, I would hands-down recommend a booster shot," he said. "But I'm not comfortable giving a universal, broad recommendation for all adolescents at this point, until we have enough data."