Covid-19 Vaccine Makers Turn Toward Testing Children

The omission of children in U.S. vaccine trials so far worries public-health experts, who say they don’t know whether the vaccines are safe for children or need changes to dosage levels. While children are less likely than adults to fall gravely ill or die because of Covid-19, researchers say, vaccinating them will help prevent the spread of the virus and achieve herd immunity. 

Yet some experts don’t expect a children’s vaccine will be ready by the 2021 school year because of how long trials take, even on the accelerated timeline for Covid-19 vaccines. “I’m pretty worried that the window’s closing if it hasn’t already closed,” said Evan Anderson, a pediatrics professor at the Emory University School of Medicine. “The timing then becomes a challenge in order to achieve enough data such that you’ve had a vaccine fully tested and evaluated over the spring and summer.”

The American Academy of Pediatrics recently sent a letter to federal officials urging children to be included in clinical studies. In the letter, AAP noted that more than two-thirds of the children who died from Covid-19 infections were Black or Latino.

The first vaccine shots in the U.S. are expected to go to high-risk populations such as long-term-care residents and health-care workers. A National Academy of Medicine panel that crafted a plan for prioritizing vaccine distribution included children in its third of four phases, after essential workers such as teachers but before most of the general population.

The Food and Drug Administration has said it is important for drugmakers to test their shots in children. It has provided few details about how to do so and hasn’t said whether vaccine makers must collect results from thousands of children or merely hundreds.

Matthew Huang, a 15-year-old from Cleveland’s suburbs who attends school virtually, jumped at the opportunity in October to enroll in Pfizer’s trial when his doctor’s office asked for volunteers. Unable to play cello or piano with friends for months because of the virus, he wanted to help researchers find a solution to the pandemic.

“I was like, yes, immediately,” said Matthew, an aspiring physical therapist whose 8th-grade school project last year was on vaccine safety. “Participating in this is really important to help others.”

The fear that children would transmit Covid-19 was initially central in the debate on how to operate schools without them becoming hot spots for the virus. But transmission rates within schools that have reopened since the fall have been much lower than those in the wider population. The coronavirus also appears to cause less harmful effects in children. Through July, just 121 of the approximate 190,000 deaths in the U.S. at the time for Covid-19-related reasons included children under the age of 21, according to the CDC.

Still, more than one million children in the U.S. have become infected, according to the AAP, and research shows children are more likely to be asymptomatic or have milder symptoms than adults. Health experts note that the number of Covid-related deaths among children has almost surpassed the range of flu-related deaths for children, which has ranged from 37 to 188 since the 2004-05 flu season, according to the CDC.

“I know there’s a perception that kids are just running around asymptomatic, but there are kids who get really sick from this,” said Grace Lee, a Stanford University professor of pediatrics who sits on the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices. “We want to be able to protect as much of the population as possible. Only protecting adults doesn’t make sense as a public-health intervention.”

Pediatricians and health experts say studies on children should begin because there is sufficient safety data on the most advanced shots. They also point to how childhood vaccines that proved to be effective for measles and polio didn’t have to show efficacy in adults first.

“For most vaccines there is not much of a reason to think that if they are safe in adults, they wouldn’t be safe in children,” said Sean O’Leary, a professor of pediatrics at the University of Colorado School of Medicine and vice chairman of the American Academy of Pediatrics’ committee on infectious diseases.

Vaccines are proven to save children’s lives. About 21 million hospitalizations and 732,000 deaths were prevented among children born during a 20-year-period because of vaccines, according to the CDC.

Vaccine experts say pediatric trials could start with older children before gradually moving down to younger groups and adjusting dosage levels.

Pfizer, whose vaccine was 95% effective in its late-stage trial, began enrolling children as young as 16 years old in September, and 12 and up the next month, after internal discussions over the challenge education officials faced with school openings, said Kathrin Jansen, who leads Pfizer’s vaccine R&D. Pfizer’s analysis for emergency authorization included some data on 100 children between 12 and 15, and no serious safety concerns arose. A pediatric trial is planned, Pfizer says.

The vaccine from the University of Oxford and AstraZeneca, which has shown to work in adults, is slated to be tested in children in the U.S., according to the drugmaker. Johnson & Johnson, which hasn’t released data for its vaccine yet, plans to start a trial for children 12 to 18 once regulators sign off, and eventually younger children, too, according to the company.

Matthew, who enrolled at Senders Pediatrics in South Euclid, Ohio, said he experienced mild side effects after both doses, such as a fever, but he recovered in about two days. He said he hasn’t really changed his behavior, although his mother, Molly, said the family now relies on him to buy groceries since they are convinced he got the vaccine and not a placebo.

“We give him a list, and we park at the grocery store,” she said. “We let him go in and pick up the groceries instead of me.”

Write to Jared S. Hopkins at [email protected]