Millions of adults get vaccinated against COVID-19 in the U.S. 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 announcement comes months after 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,” said Moderna CEO Stéphane Bancel.
A Pfizer spokesperson, meanwhile, said the company has finished enrolling participants for its trial with teenagers ages 12 to 15.
But as states are pressured to send kids back to school, parents are wondering when their children will be able to get the COVID-19 vaccine. Here’s when experts think that will happen:
When can kids get COVID-19 vaccine?
The Moderna and Johnson & Johnson vaccines are cleared for people 18 and older, while the Pfizer vaccine is authorized for ages 16 and up.
Both 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 coronaviruses among teens from 12 to 17 years old were twice that of children ages 5 to 11 from March to September 2020.
Vaccines tend to be tested in adults and then teens before being tried in younger children and babies, who may need lower doses or have different reactions.
While 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 then, 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 pediatric populations,” according to a statement sent to USA TODAY on Tuesday.
Are COVID-19 vaccines safe for kids?
Health experts say the vaccines are likely to be as safe for kids as they’ve proven to be safe for adults.
“That’s going to be a fact,” Frenck said.
Over 109 million doses of COVID-19 vaccines have been administered in the U.S, the CDC reports. During this time, the agency received 1,913 reports of death among people who received the vaccine but found no evidence that vaccination contributed to patient deaths.
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 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?
While the composition of the vaccines themselves may not change, the dosage might, experts say.
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.
However, he emphasizes COVID-19 in children is still worse than the flu.
While 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 to 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.”
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 say.
“You need to have more of a justification as to why you are testing vaccines in kids,” Frenck said.
Although the trials didn’t occur simultaneously, experts say the adolescent and pediatric trials won’t take nearly as long as the adult trials because the trials 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. But for adolescent trials, the companies will need about 3,000 and 2,600, respectively.
Researchers also 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 the child’s immune response and compare to 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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