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With several coronavirus vaccines in advanced trials, adults could receive an approved vaccine within months. But even then, we probably don’t know if any of these vaccines work in children.
Just a handful of coronavirus Vaccine trials currently include children as participants; one of them is an Oxford-AstraZeneca essay, Stat News reported. The Chinese company Sinovac Biotech will include children from 3 to 17 years in an upcoming test, according to ClinicalTrials.govBut overall, most vaccine developers have not launched similar trials with participants under 18 years of age. And in the US, no children have been enrolled in coronavirus vaccine trials, The New York Times reported.
Vaccines are generally tested in adults before children to allow their safety profiles to be fully evaluated and their potential risks minimized before they are administered to children. In the case of COVID-19, children generally face a much lower risk of hospitalization and death compared to adults, so taking an untested vaccine could pose higher risks than the virus itself. That said, with data from large adult trials coming in, some experts have argued that vaccine Rehearsals for children should start sooner rather than later.
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“The sooner the better,” said Dr. Flor Munoz-Rivas, associate professor of pediatric infectious diseases at Baylor College of Medicine in Houston. Given the first data collected in late-stage adult trials, which include thousands of participants, vaccine developers could launch trials for children older than 12 to 17 years, he said. If a vaccine appears safe and effective in this group, trials could continue in increasingly younger children.
In a comment, published on September 18 in the magazine Clinical infectious diseases, Muñoz-Rivas and his colleagues argue that coronavirus vaccine trials for children “should start now.” Delaying such trials could mean delaying “our recovery from COVID-19 and unnecessarily prolonging[ing] its impact on the education, health and emotional well-being of children, “they wrote.
The sooner the better?
Although adult hospitalization rates for COVID-19 far exceed those of children, that does not mean that children are not adversely affected by the disease. Child hospitalization rates for COVID-19 are comparable to those for diseases such as chickenpox, Hepatitis A and rotavirus, before vaccines for those infections were widely used, the comment notes.
Additionally, about a third of children who are hospitalized with COVID-19 end up in intensive care, the authors add. And some infected children develop a condition known as multi-system inflammatory syndrome in children (MIS-C), in which inflammation throughout the body causes skin rashes, high fever and abdominal pain, among other symptoms, Live Science previously reported. In a recent MIS-C study associated with COVID-19, published in The New England Journal of Medicine, 80% of the affected children were admitted to the ICU.
By early September, more than 100 children had died from COVID-19 in the United States, the authors noted. That compares to 188 children who died during the 2019-2020 flu season, according to the Centers for Disease Control and Prevention. “Right now, [both diseases] they appear to be similar in terms of mortality, but of course, the flu is present for a limited period of time, while the circulation of COVID is ongoing and we don’t know how long it will last, “Muñoz-Rivas said.” The potential to overcome the flu is there, in my opinion. “
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An approved vaccine would not only protect children against potential illness and death, but would also reduce the spread of COVID-19 from children to others and allow schools to resume safely with fewer distancing measures in place, Dr. Steven Joffe, a professor of bioethics and pediatrics at the University of Pennsylvania Perelman School of Medicine, wrote in a comment on The Washington Post.
“They can definitely transmit the infection, especially to older children,” Muñoz-Rivas noted.
It is not yet clear how often children under the age of 10 contract and transmit COVID-19, but in a Weekly morbidity and mortality report, released Sept. 28, researchers describe how older teens may be as likely as adults to transmit the virus. Without a vaccine approved for children under 18 years of age, the effort to curb the viral spread of children will continue to rely on other countermeasures, such as social distancing and wearing a mask, Joffe wrote.
Essays for children
Once trials for children take off, enrolling participants may take longer than with adult vaccines, Muñoz-Rivas noted. Trials of the COVID-19 vaccine for adults have enrolled thousands to tens of thousands of participants in a matter of months, but “the pace of conducting a pediatric study is usually not that fast,” he said. For a child to participate in a trial, their legal guardian must consent on their behalf, and children 7 and older must also agree to participate after receiving a detailed explanation of the study’s requirements and risks, she said.
Even with this complicated registration process, during 2009 H1N1 pandemic, “we go very quickly from adults to children, and then to different age groups,” Muñoz-Rivas said. In one trial, “we enrolled hundreds of children in two weeks.” Initial trials of COVID-19 vaccines in children would likely enroll a few hundred participants, he said.
Typically, after trials in children ages 12 to 17, vaccine developers move on to children ages 5 to 12, then children under 5 years of age. “Very young babies are not likely to be part of the studies from the beginning,” Muñoz-Rivas said.
Like trials with adults, trials with children aim to find the safest and most protective dose for a given vaccine, but data already collected in adults can indicate which dose might be the best. Children in the first trials receive smaller doses than adult participants, and if they do not have harmful side effects, the trial leaders gradually increase this dose. At the same time, the trial leaders control the amount of antibodies children produce with each dose given; thanks to your youth immune system, children may not need as high a dose as adults to elicit a strong immune response, Muñoz-Rivas said.
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That said, this initial immune protection could wear off over time, as studies suggest that immunity to seasonal coronaviruses may be short-lived. Live Science previously reported. Immunity to COVID-19, whether obtained through a natural infection or a vaccine, can also decline over time.
So, after receiving an initial COVID-19 vaccine, both children and adults may need booster shots in the future, Muñoz-Rivas noted. Similarly, older children receive boosters for chickenpox and whooping cough after receiving their initial doses in infancy. If possible, both children and adults participating in COVID-19 trials should be monitored after their vaccination, for up to about 10 years, to determine when and if a booster is necessary, Muñoz-Rivas said. The timing and dose of these boosters may differ between adults and children, depending on their initial immune responses to the vaccine, she added.
As in adult trials, vaccine developers need to be vigilant about short-term and long-term side effects that arise in vaccinated children. Mild side effects can include a mild fever, muscle aches, or injection site pain, as seen in adults, while a severe reaction can include severe inflammation or an exaggerated immune response.
Since vaccines trigger the production of antibodies that attack the coronavirus, vaccine developers must ensure that this immune response is strong enough to be protective, but strong enough that it is harmful to the child.
For example, although the exact cause of MIS-C is unknown, a recent study found that children with the condition have high concentrations of specific antibodies in his blood; These antibodies adhere to part of the virus called the “receptor-binding domain” (RBD), a primary target for vaccines. The new study did not show whether these antibodies actually why MIS-C: may be just a sign of the disease, but in a comment accompanying the report, experts cautioned vaccine developers to watch for any symptoms of MIS-C in vaccinated children. The concern would be that a vaccine could boost the production of specific antibodies against RBD and that it would somehow boost the emergence of MIS-C, but this is highly theoretical and may not result in any risk, Muñoz-Rivas noted.
“The question is, ‘How well do we understand the mechanism?'” How MIS-C occurs, Muñoz-Rivas said. “It’s not necessarily an antibody problem,” and most likely an effective vaccine would help protect children from MIS-C by protecting them from getting COVID-19 in the first place, she said. Given the direct benefits to children and the indirect benefits to those with whom they interact, pediatric trials of COVID-19 vaccines should begin as soon as possible, she and her co-authors wrote.
“For children, a vaccine has the added benefit of returning them safely to school and extracurricular activities, and allows them to interact with their world face to face once again,” they wrote. “Ensuring acceleration of vaccine clinical trials to accelerate the speed for children will be critical to making this our future reality.”
Originally posted on Live Science.
