CLEVELAND, Ohio — With anyone over the age of 12 eligible for a COVID-19 vaccine, attention has turned to when younger children can get the shot.
The answer could be sometime this fall.
Ohio sites are part of the first clinical trials to evaluate the vaccine in children between 6 months and 12 years old. Those sites, including Sender’s Pediatrics in South Euclid, could begin phases 2 and 3 of the trial in the coming weeks.
Pfizer has said it could apply for an emergency use authorization for children who are at least 2 years old before the beginning of the fall, and for children aged 6 months to 2 years before the end of 2021. Moderna has not said when it might be ready to request a similar endorsement.
Getting a vaccine approved for young children could be key to recovering from the coronavirus pandemic, experts say.
While the US is on the cusp of administering at least one vaccine dose to half of the population, it is estimated that about three quarters will need to be fully vaccinated to achieve herd immunity. Immunizing children, in reducing transmissions, could also reduce the risk of more dangerous mutations developing. And while data has shown that the virus is less likely to cause serious illness in children, it can still cause serious complications.
For those reasons, many parents would like to know when their children are eligible for a vaccine.
There is a lot of interest at Aventiv Research in Columbus, one of four Ohio sites involved in the evaluation of the Pfizer vaccine, said the organization’s president and medical director, Dr. Samir Arora.
“We have had a lot of interest. I think we have 400 children waiting to hear from us about this study,” said Arora, whose organization is involved in phases 2 and 3 of the Pfizer study. “I think a lot of the parents who participated in the adult study want to have their kids in this study.”
The Cincinnati Children’s Hospital has been involved in Phase 1 of the Pfizer trial since March and was also part of the previous studies for adults and older children. While many parents have questions about the vaccines, interest in the pediatric trial is very high, said Dr. Paul Spearman, the director of the infectious disease division at Cincinnati Children’s.
“I think there are some parents – and it’s important for us to deal with this along the way – who are nervous or hesitant about the vaccine. But there are also people who are very interested in getting their children vaccinated so they can be protected and things can get back to normal,” Spearman said. “It’s that group that we really hear a lot from now.”
All vaccines must undergo extensive clinical trials before they are available to the public, and the COVID-19 vaccines were no exception. However, many parents will likely have questions about how those studies are conducted and whether their child should eventually take the coronavirus vaccine. Cleveland.com spoke to doctors involved in the Ohio Pfizer trial to provide context.
Where will the trials take place and who will be involved?
Pfizer’s trial is taking place in at least 67 locations, including 58 in the US and nine in Spain. At least four of those locations are in Ohio, including Senders Pediatrics in South Euclid, plus Aventiv Research in Columbus, Cincinnati Children’s Hospital and PriMed Clinical Research in Dayton.
Arora, Spearman and Dr. Shelly Senders of Senders Pediatrics told cleveland.com that they expect Phases 2 and 3 of the Pfizer study to begin sometime in the coming weeks. Aventiv and Cincinnati Children’s are already collecting information from potential volunteers on their websites, but Senders has not started recruiting yet.
Moderna’s trial takes place at 32 locations in the US. None of them are located in Ohio.
The Pfizer trial is expected to include at least 4,600 participants, while the Moderna trial will include more than 7,000.
All children in both studies must be healthy. And they can’t participate if they’ve had COVID-19. The child’s immune system would already be familiar with the immune response the COVID-19 vaccine is trying to generate because of the previous infection, which could obscure the data.
Exactly how many children will be enrolled at each Pfizer location in Ohio has not been determined. Arora said Aventiv Research hopes to start with 40 children, while Spearman said the Cincinnati Children’s Hospital expects between 30 and 50. Senders believes that each location will eventually have more than 25 or 30 children.
How are the pediatric clinical trials set up?
The pediatric studies are similar to those involving adults and teens, with some changes. One of the most notable differences is the fact that a parent or guardian must give permission for the child to volunteer.
The pediatric studies are still double-blind, randomized placebo studies. That means neither the researchers nor the participants know whether the participant has been assigned to receive the vaccine or a placebo.
They also still include three phases. In Phase 1, the goal is to identify the appropriate amount of vaccine to be administered in each dose and to evaluate the vaccine for safety. During phases 2 and 3, the vaccine is evaluated for its safety, tolerability and the immune response it generates.
The pediatric studies include methods known as age reduction and dose escalation. The children are divided into three age groups: 5 to 11 years, 2 to 5 years and 6 months to 2 years. The researchers start by evaluating the oldest children before moving on to the youngest.
In each age group, the children receive a low, medium and high dose of the vaccine. The goal is to identify the correct dose that will provide the most benefit while limiting any adverse side effects. In the Pfizer study, the highest dose given to the children is the same 0.3 ml dose approved for use in anyone over the age of 12.
The age de-escalation/dose escalation strategy is common in pediatric clinical trials because it has been proven to be effective and safe, Senders said.
“This is a well-practiced approach,” says Senders, whose practice was also part of the evaluation of the Pfizer vaccine for adults and older children.
Pfizer’s pediatric study is much smaller than the adult study, which involved more than 44,000 volunteers. For that reason, scientists will focus on whether the immune response the vaccine generates in children is similar to that in adults. If it’s the same, they can extrapolate that the vaccine will be equally effective in children, Spearman said.
“What these studies are going to do is build a bridge to the older groups, especially the young adult group, to ensure that each of these age groups can generate antibody responses that are at least as good as the young adult group,” Spearman said. .
How the vaccines are assessed for safety and effectiveness
Because the studies are in the early stages, doctors said it’s too early to speculate about the immune response they’ll elicit in children, or whether any side effects are similar to those seen in other age groups.
Senders noted that children are not “little adults.” They have different immune responses and sometimes respond differently to drugs. So it is important to do a thorough assessment.
“We really need to find out whether the [vaccine] protection is the same, whether the dose should be the same and whether the side effects are the same or different,” he said. “Once you know that, we can safely use it in those [younger] age groups.”
The Pfizer study of children between the ages of 12 and 15 found that they had a stronger immune response to the vaccine than teens and young adults. Side effects were more common in adolescents, but they were still the side effects commonly seen in adults, such as fatigue, chills, and injection site pain.
One of the main concerns regarding the COVID-19 vaccines – often used by anti-vaccination advocates – is that they were “rushed” as they were allowed to be used in emergency situations less than a year after the clinical trials started. But the Ohio doctors involved in the Pfizer study said they are very confident in the way it was designed and executed.
“Yes, it could have accelerated over the course of 11 months,” Arora said. “But everything happened with a level of precision.”
There are several reasons why the vaccines were approved more quickly. Scientists were able to build on research from previous coronaviruses, such as the ones that caused SARS and MERS. Vaccine development has also been a global focus, with efforts such as Operation Warp Speed in the US providing funding and helping to remove administrative hurdles.
Scientists were also able to combine some phases of the clinical trials to speed up the process. But that didn’t mean we had to skip security checks — those same steps just happened faster, Senders said.
“From my perspective of someone who has done more than 200 trials, this trial was not rushed,” Senders said. “This trial was done in the same way as any other trial, except it was done in real time.”
The benefit of children receiving the COVID-19 vaccine
While data has shown that children are significantly less likely to have a severe case of COVID-19 that could lead to hospitalization or death, doctors emphasized that this is not a guarantee. According to data from the National Center for Health Statistics, there are 300 deaths related to the coronavirus among children and teenagers in the US.
In addition, some children have developed a rare but serious complication called multisystem inflammatory syndrome, a condition that causes the immune system to kick in and attack other organs. And some hospitals have opened pediatric “long-hauler” wards for children with lingering effects of infection.
“I wouldn’t want my child to be the only child who [multisystem inflammatory syndrome] or a long-hauler syndrome,” Arora said. “If we have something that could prevent our kids from getting it, why not?”
Senders said he has had many discussions with parents asking whether they should have their child take a coronavirus vaccine as soon as one is available. He tells them it will help children lead normal lives and alleviate worries that they could contract COVID-19.
Doctors also noted that there are several unknowns related to the coronavirus, which could make childhood vaccinations more important.
It is possible that the virus will continue to mutate and that a future variant poses a greater threat to children. It’s also unclear how long the vaccine will provide protection to those who have already used it, so vaccinating as many children and adults as possible could ultimately reduce transmission and protect those most vulnerable, such as older adults.
“Although children are much less likely to get the disease than older individuals, we are still seeing significant illness and some deaths in pediatric populations. We can’t ignore the fact that it’s still a pathogenic virus in our children,” Spearman said. we protect the children ourselves, and also do something good to fight the pandemic.”