Millions of adults get vaccinated against COVID-19 in the USA each day, but trials are still underway to determine the safety and effectiveness of the vaccines in children.
Moderna announced Tuesday it has given the first doses of its COVID-19 vaccine to children under 12 years old. The company launched a trial in 12- to 17-year-olds in December 2020.
“This pediatric study will help us assess the potential safety and immunogenicity of our COVID-19 vaccine candidate in this important younger age population,” Moderna CEO Stéphane Bancel said. Immunogenicity is the ability to trigger a body’s immune response.
A Pfizer spokesperson said the company finished enrolling participants for its trial with teenagers ages 12 to 15.
As states are pressured to send kids back to school, parents wonder when their children will be able to get a COVID-19 vaccine. Here’s when experts expect that will happen:
When can kids get COVID-19 vaccine?
The Moderna and Johnson & Johnson vaccines are cleared for people 18 and older, and the Pfizer vaccine is authorized for ages 16 and up.
Moderna and Pfizer have completed enrollment for studies of children ages 12 and older and expect to release the data over the summer. If regulators clear the results, younger teens could start getting vaccinated once there’s enough supply.
“For kids 12 and above, I think we’ll have a vaccine licensed before the 2021-2022 school year,” said Dr. Robert Frenck, director of the Gamble Vaccine Research Center and principal investigator for the Pfizer COVID-19 vaccine trial at Cincinnati Children’s Hospital Medical Center.
There is growing evidence that teens are more likely to transmit COVID-19. A report from the Centers for Disease Control and Prevention found about twice the incidence of COVID-19 among teens 12 to 17 years old than in children ages 5 to 11 from March to September 2020.
Vaccines tend to be tested in adults, then teens, before being tried in younger children and babies, who may need lower doses or have different reactions.
Moderna has begun vaccinating younger children in its trials. A spokesperson for Pfizer said the company hopes to have data from 12- to 15-year-olds in the first part of this year and, based on those findings, could start a trial in younger children.
Neither company confirmed a timeline, but Frenck guessed a vaccine for younger children may be available in spring 2022, or “maybe a bit sooner.”
J&J said the company is in “discussions with regulators and partners regarding the inclusion of pediatric populations,” according to a statement sent to USA TODAY on Tuesday.
Dr G. Paul Evans, CEO of Velocity Clinical Research, which is running trials in children ages 6 to 11 for many of the companies, said in an email that it may be trickier to recruit younger children than teens, “because of the hesitation that parents naturally have, when considering allowing their children to take part.”
But, he added, that parents are eager to get their children vaccinated. “Parents don’t want to keep home-schooling children and want their kids to socialize again,” he said.
Are COVID-19 vaccines safe for kids?
Health experts said the vaccines are likely to be as safe for kids as they’ve proved to be for adults.
“That’s going to be a fact,” Frenck said.
More than 109 million doses of COVID-19 vaccines have been administered in the USA, the CDC reported. During this time, the agency received 1,913 reports of death among people who received the vaccine but found no evidence that vaccination contributed.
The vaccines are undoubtedly safe among adults, said Dr. Cody Meissner, chief of pediatric infectious diseases at Tufts Children’s Hospital, but he’d like to see robust trials that prove safety and efficacy among adolescents and children before making a similar claim.
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“Some degree of hesitancy for vaccinating children is proper,” he said. “We need vaccines for children because we want to generate herd immunity, there’s no question. But we need to do that safely.”
Frenck said trial participants are mostly healthy without underlying medical conditions, but he hopes to expand trials to children who may have compromised immune systems by the summer.
Are there any differences between the vaccines given to kids versus adults?
Though the composition of the vaccines may not change, the dosage might, experts said.
Teens are likely to get the same dose as adults, but children under the age of 12 may be given a lower dose.
In younger kids, researchers may start with a quarter of the regular dose, Frenck said. If things look OK, they may decide to increase the dose in that same age group or move down to the next age group.
Younger kids may end up with a lower dose because their immune response works well against COVID-19. This isn’t the case with all vaccines.
“If you look at the flu vaccine, we use the same dose of flu vaccine in a 6-month-old as we do in a 64-year-old,” Frenck said.
He emphasized COVID-19 in children is worse than the flu.
Though COVID-19 is generally mild in children, in rare cases, it can cause serious disease and even death. More than 260 children have died from the coronavirus compared with 188 children from the flu during the 2019-2020 season, according to data from the CDC and the American Academy of Pediatrics.
“If you compare (260) to 500,000 deaths, it’s a very small number,” Frenck said. “But these are kids that were perfectly healthy until they got COVID.”
Babies under six months are not included in the vaccine trials, because they are generally presumed to have some antibodies from their mother, which will provide protection but could also interact with a vaccine, potentially causing problems, said Dr. Sallie Permar, chair of pediatrics at Weill Cornell Medicine and NewYork-Presbyterian Komansky Children’s Hospital.
“It will be interesting to see if there’s any hint of that” kind of issue with COVID-19 vaccines, she said. On the flip side, infants might end up needing a booster shot, if their mothers’ antibody protection doesn’t last long enough.
She said she also think young children should be given a lower dose of the vaccine than older children or adults. In her own research with HIV, Permar said she found that “children can respond well to low-doses of protein-based vaccines.”
Why couldn’t adult and pediatric trials happen at the same time?
Researchers needed data from the adult trials to understand a degree of safety and effectiveness before moving forward with adolescents and younger children, health experts said.
“You need to have more of a justification as to why you are testing vaccines in kids,” Frenck said.
Experts said the adolescent and pediatric trials won’t take nearly as long as the adult trials because they don’t require as many participants as the Phase 3 trials in adults.
Moderna and Pfizer took months to recruit 55,000 adult volunteers for Phase 3 trials. For adolescent trials, the companies will need about 3,000 and 2,600, respectively.
Researchers don’t want to wait for trial participants to come in contact with someone infected with COVID-19 to determine the vaccine’s efficacy, unlike the adult trials. Instead, they’ll measure children’s immune response and compare it with the adults’.
“If you get the same immune response, then the extrapolation is that you have the same protection,” Frenck said.
Contributing: Karen Weintraub, USA TODAY
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
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