The Register Citizen (Torrington, CT)
Doc: Kids key to herd immunity
Conn. children involved in vaccine trials for youth
NEW HAVEN — To reach herd immunity against COVID-19, vaccine researchers are aiming younger.
Onyema Ogbuagu, a Yale New Haven Hospital infectious disease physician and associate professor of medicine at Yale University, said youths are critically important for reaching herd immunity from the virus — which will occur when about 70 percent of the population has some immunity. According to U.S. Census Bureau estimates, more than one in five Americans is below the age of 18.
“Without kids, it will almost be impossible to achieve that target,” he said.
Ogbuagu, who led the first Pfizer-BioNTech vaccine trial at the Yale Center for Clinical Investigation, also has enrolled 20 Connecticut children between
“We really had a barrage of parents who expressed interest in the study, way more than we could enroll in the study.”
Onyema Ogbuagu, Yale New Haven Hospital infectious disease physician, Yale University associate professor of medicine
the ages of 12 and 15 in a clinical trial to test the efficacy of the vaccine in younger populations.
Overall, 2,259 children in that age group were added
clinical trials for the Pfizer-BioNTech vaccine across 153 trial sites in six countries.
Yale declined to make any trial participants available to the press.
But Ogbuagu said the trial was extremely easy to enroll, filling up mostly with the children of adult participants from prior clinical studies or through word of mouth. He estimated there were roughly 35 volunteers between 12 and 15 who were not taken after the local trial had fully enrolled.
“We really had a barrage of parents who expressed interest in the study, way more than we could enroll in the study,” he said.
Even once there is approval to use COVID vaccines on children as young as 12, Ogbuagu said, the work does not stop there.
“We also are considering clinical trials that will enroll kids from age 5 to 11, and we’re even in early conversations about going down to kids less than age 5,” he said.
Keanna Ghazvini, a spokeswoman for Pfizer, said the company intends to share its results from the 12to 15-year-old group in the first half of this year, before beginning a pediatric study on children ages 5 to 11.
“Global regulatory agencies require evaluation of the candidate vaccine in pediatric populations. Moving below 12 years of age will require a new study and potentially a modified formulation or dosing schedule. We’ll be able to finalize those plans more so, in the coming months, when we have data from the 12-15 year old cohort,” she said in an email.
Priorities
Ogbuagu said both doses of the vaccine were administered to the volunteers by his research team at his research sites in New Haven. As of late this month, he said he his team has begun a one-month followup after administering the second dose to the 20 volunteers.
“They all anecdotally tolerated the vaccine well,” he said.
As the actual vaccination process at New Haven’s site is complete, Ogbuagu said, his team now is tasked with monitoring and reporting symptoms of participants. For the trial, the young participants received the same dosage as adults, he said.
Ogbuagu said it is typical for most clinical trials to begin using volunteers age 18 or older.
“Vaccines are typically tested in older individuals first — usually adults above the age of 18 — and after the safety and efficacy has been established in those groups, then it is extended to younger children and adolescents,” he said.
For a disease like COVID-19, which has been shown to be deadliest and most debilitating in older populations, Ogbuagu said it was a priority to begin vaccinating adults first following emergency use authorization from the U.S. Food and Drug Administration.
“(Children) would not be considered a high-priority group for vaccination, even if the emergency use authorization expanded to cover them,” he said.
“However, kids do, in spite of not falling seriously ill or dying from the disease, transmit the virus between each other and also to their parents, grandparents and school teachers,” he said.
Further, despite the sigto nificantly lower rates of fatalities from COVID-19 among children, research has shown that the virus can have a serious impact on their health. According to research published in the journal JAMA, some children who tested positive for the coronavirus began to feel the effects of a severe inflammatory syndrome weeks later.
Immunity
Tom Murray, associate medical director for infection prevention for Yale New Haven Children’s Hospital, said vaccines may have a different level of effectiveness in children than in adults.
“We know a child’s immune system is developing and their immune system, especially the younger children, is not comparable to adults,” he said.
Because of those healthier immune systems, Murray said young children sometimes can get the full benefit of a vaccine with a lower dose.
However, Michael Urban, a senior lecturer and director of the University of New Haven’s Doctorate in Occupational Therapy program, said children’s developing bodies could mean immunity they receive from the vaccine might not last as long as in an adult. Although research still is being done through the clinical trials, Urban said there is a possibility young people may require a booster shot after initial vaccination.
“We’re still learning stuff today about the effects on middle-aged adults,” he said.
“For kids, they joined the study late, so anything that comes through about longterm effects for children, we probably won’t know for another six months, maybe, at the earliest,” Urban said.
Murray said it’s not unusual to enroll children without underlying health conditions in broad-based trials first, before expanding it. However, he doesn’t anticipate that will be a barrier for the various COVID-19 vaccines.
“It’s been such a safe vaccine,” he said. “I would expect it will be as safe as it has been for adults.”
Consent
According to Pfizer, the racial makeup of participants in all of its clinical trials has been varied. Of the 46,331 enrolled in all clinical trials for the vaccine, 10 percent have been Black participants and 26 percent have been Hispanic or Latino.
Urban said it reflects well on the studies that they can demonstrate the efficacy of the vaccine on a variety of racial and ethnic populations.
Angela Mattie, a professor of management at Quinnipiac University, said one challenge around conducting clinical trials with children is the issue of informed consent.
“Legally, if your kid is under the age of consent then it’s the parent or guardian that can provide informed consent,” she said.
She said it’s paramount that parents have a full understanding of what it means that their child will be inoculated during the trial.
Ogbuagu said that, although parents must provide consent, the children volunteers of studies must at least provide assent, indicating they are aware of what will be done in the trial and they are in support.
Heather Joseph, a New Haven mother, said she would not want have wanted her 14-year-old son to be a part of the clinical trial because she believes there first needs to be more information on how the vaccine affects adults. However, she said she is eager for her son to receive the vaccine.
“I just want the people to live together, not die alone,” she said.
She said her son already is vaccinated for polio and chicken pox, so she does not mind him receiving a vaccine for something else.
“Why not avoid the hospital ventilator?” she said.
New Haven school leaders have not made clear when high school students will be welcome to return to their buildings, but Joseph said she is fine with waiting until her son is inoculated.
Mattie said that, once the vaccine receives approval for children younger than 16, equity should be a strong consideration in deciding how the vaccine ultimately should be administered.
“I would think about how we make it easiest for parents, especially those parents with busy schedules that don’t have help in the house,” she said.
Mattie said schools can be good locations for vaccination sites, as are community health centers.