Over the last year, a heroic effort has brought about multiple safe and effective vaccines that offer excellent protection against COVID-19. States and the federal government have made considerable progress rolling out these vaccines to adults to help finally end the coronavirus pandemic.
So far, only people over the age of 16 have been able to access the shot, which has many people asking when they’ll be able to get their kids vaccinated.
Dr. Alex Li, a board-certified pediatrician and internist and deputy chief medical officer of L.A. Care Health Plan, the largest publicly operated health plan in the country, says that many people associate vaccines with childhood. “Most vaccines, such as for chickenpox, measles and so on, are infections that are more deadly and mostly affect children. Additionally, many vaccines are administered during childhood so that kids can develop life-long immunity. Thus, there is a perception that vaccines are only for kids,” Li says. One exception is the shingles vaccine.
COVID-19 is different from diseases like the mumps and rubella because the virus has predominately impacted older people.
The Centers for Disease Control and Prevention reports that 8 out of 10 COVID-19 deaths have been in adults age 65 and older in the U.S. That burden of disease is a major reason why adults were prioritized over kids for the COVID-19 vaccine, Li says.
“Although anyone can get infected by the COVID-19 virus, we saw early on in the pandemic that COVID-19 was particularly devastating for older adults, those 65 and older, and for people with chronic health conditions. Most of those who were hospitalized or died were older adults and/or those with chronic health conditions.”
Still, some children have gotten very sick and roughly 250 have died in the U.S., says Dr. Octavio Ramilo, chief of infectious diseases at Nationwide Children’s Hospital in Columbus, Ohio. Children need to be protected, and “they deserve to be vaccinated.”
But because their incidence of illness and death has been significantly less than in adults, starting with adults — and indeed older adults with risk factors for more severe outcomes — made sense.
But now that all adults are eligible to receive the vaccine, it’s time to start bringing kids into the mix.
Testing a New Technology
The next step towards opening up vaccine eligibility to children depends on a determination about the safety and efficacy of the vaccines in this younger population, says Dr. Vidya Mony, a pediatric infectious disease specialist with Santa Clara Valley Medical Center in San Jose, California.
Clinical trials “usually start in healthy, immunocompetent adults,” and upon successful completion of those initial trials, additional trials are expanded to “special populations such as children, pregnant people and the immunocompromised,” she says.
This is the standard approach within the pharmaceutical industry, says Dr. Pamela Zeitlin a pediatric pulmonologist with National Jewish Health in Denver. “New molecules are tested first in adults and then marched down through adolescence to lower and lower ages. In this case, drug companies could have included some of the older teenagers in their clinical trials, but they started with adults, I think, because the mRNA vaccines are so new.”
Lynne Georgopoulos, a registered nurse and VP of regulatory strategy at Certara, a drug discovery accelerator headquartered in Princeton, New Jersey, says the first two vaccines that were authorized for use in the United States — one made by Pfizer-BioNTech and the other by Moderna — both used this ” novel RNA vaccine platform. Prior to the COVID-19 vaccine, there were no licensed RNA vaccines on the market,” and the limited clinical data made it “difficult to speculate” how children’s responses to the vaccine would compare to that of adults.
Though the vaccines are very new, that doesn’t mean they haven’t been rigorously tested, Ramilo notes. “For years, people have been preparing all the tools to apply for this particular virus. A lot of the technology and ideas have been worked on for years. So, it’s not like everything happened out of the blue. There was a lot of background work for many, many years that allowed this to happen.”
Plus, some of the steps along the path to vaccine authorization have been taken in parallel to save time, Ramilo says. “At the same time that they were doing ‘A,’ they were doing a little bit of ‘B’ and ‘C.’ They were not waiting until ‘A’ was completely done to start ‘B.'” This helped condense the timeline while retaining the same safety measures.
“Before vaccinating children, vaccine developers must complete the necessary clinical trials, to demonstrate that the vaccine is safe and effective in children, and the data must then be reviewed by the (U.S.) Food and Drug Administration,” Georgopoulos says. “The dose and design of these trials are based on information learned from studies in adults.”
Current Vaccine Trials in Adolescents and Children
Mony summarizes that Pfizer “has already enrolled participants between the ages of 12 to 15 with great phase 3 data.” Phase 3 data means the trials have included a large number of people and have completed the end of the three-step clinical trial process. From there, the data can be reviewed by the FDA and the vaccine or medication considered for use in a specific population.
Moderna has already enrolled 12- to 17-year-olds, and both companies have now started to enroll participants six months to 11 years old for additional study.
Janssen, the maker of the one-shot Johnson & Johnson vaccine that uses a different method to encourage the development of antibodies from the other two vaccines, “has already described plans to enroll children and adolescents,” Mony says.
Clinical trials are currently looking at how much vaccine children at various ages need to develop antibodies and how effective those doses are, Zeitlin says. “The size of a six-month old versus a 17-year-old is quite different,” so understanding how to most effectively adjust the dose size for kids of different ages is important.
Ramilo adds that the trials are looking to test which dose is effective in which age group, but also whether the frequency or severity of vaccine side effects changes with the dose size. “If you give a bigger dose, do you have more fevers or more sore arms or adverse events? And how is the antibody response? It’s about finding the right balance” between developing as many antibodies as possible without triggering an adverse event. You test different doses on small groups of people and look at the data.”
Measuring Immune Response and Dosage in Children
Kids are different from adults, and their bodies may react differently to medications and vaccines. “It’s important to keep in mind that children are not small adults, and even among children, there can be significant differences in how various age groups — from infants to teenagers — react to vaccines and medications,” Georgopoulos says.
Ramilo says that because children are growing, the way the body reacts to any medication or vaccine may vary substantially from adults. They metabolize things differently and may need a very different dose.
This is why the vaccine makers are carefully testing the efficacy and safety of their products in progressively younger cohorts of children. “With teenagers, the immune system is closer to that of an adult,” Ramilo says. “But the minute you go down in age groups, we need to be more observant to see if the younger children also react in a similar way.”
“A ‘one-size-fits-all’ approach is not applicable when dealing with vaccines for children,” Mony says, and as a result, clinical trials are designed to provide the data necessary to know whether a vaccine is safe and effective in a certain age group. “You may not always have the same formulation of a vaccine for adults and children,” she explains. “For example, some children may need to have two doses of the influenza vaccine in order to attain the best immune response. This is not the case or recommendation from the CDC for adults.”
With COVID-19 vaccines, Zeitlin says she expects that kids will have a robust response. “I think children are at an advantage over adults in terms of their immune system using the vaccination to make antibodies.” Their young immune systems are able to pivot quickly to react to challenges, whether from pathogens or a vaccine, and that allows them to achieve a high level of protection. “Pfizer spokespeople have said they’re gratified to see that it looks to be the case, because the efficacy is higher in teenagers even than the adults,” she adds.
When Will My Kid Be Able to Get Vaccinated Against COVID-19?
When a COVID-19 vaccine will be available for kids younger than 16 is still an open question.
“Pfizer has already shown its phase 3 data in 12- to 15-year-olds, and the data is quite exciting,” Mony says. But, they still need to “have their data peer reviewed by an expert panel and then be presented to the FDA for emergency use authorization. I’m hopeful to have a vaccine for this age group before the start of the upcoming school year.”
When kids younger than 12 will be able to access the vaccine will take more study and a little more time, but Zeitlin predicts “6- to 12-year-olds will be eligible by the end of the calendar year. It’s probably too soon to say when 6 months and older would be available, but it may be a bit longer than that.” The hope is that eventually, a vaccine will be available for everyone from 6 months of age and up.
Pregnant Women and Newborns
Another point of note: The Pfizer-BioNTech and Moderna vaccines have been found to be safe and effective in pregnant and breastfeeding women. Research has also indicated that breastfeeding “mothers can pass antibodies to their newborns, which will protect them until they can get the vaccine at six months,” Georgopoulos says.
Vaccinate Your Children to Stop the Spread
If a vaccine is authorized for use in school-aged children by the time they go back to school in the fall, some schools my require that students be vaccinated to take part in any in-person lessons. Some colleges are already doing this, and it’s likely that come fall, there will still be a good bit of variation from county to county and even school to school regarding whether classes are conducted in person, remotely or using a hybrid model.
When the vaccine is authorized for children, Georgopoulos urges parents to get their children vaccinated. “The best way to stop this pandemic is to achieve herd immunity, and that won’t happen without broad vaccination among all age groups.”
Mony agrees. “As a physician and mother of two small children, much of what I do is to protect and keep my two little ones safe. I have no doubt that getting a vaccine that is considered ‘new’ is scary to many parents. However, in my opinion, the best way I can keep my children safe is to vaccinate the adults around them, and when available, vaccinate my children as well.”
Even as the number of people vaccinated here in the United States continues to climb steadily, the race is on against variants that may be more contagious and deadlier.
“I think we’re all feeling that vaccination is going to afford quite a bit of protection, but we don’t really know what position we’ll be in a year from now,” Zeitlin says. If the virus mutates in such a way that it can dodge the vaccines, additional shots may become necessary.
There’s also still an outstanding question about how long immunity conferred by the vaccines will last. Current data suggests that immunity is durable for at least six months, and time will tell whether it’s longer than that. In any event, many experts believe that people who’ve been vaccinated will require a booster dose at some point in the future, perhaps annually like with the flu shot, to maintain the antibodies needed to fight the coronavirus indefinitely.
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