Q&A: Why should children be included in COVID-19 vaccine trials?
Clinical trials investigating COVID-19 vaccine candidates continue in all phases, but none yet have included children.
Sharon Nachman, MD, chief of the division of pediatric infectious diseases at Stony Brook Children’s Hospital in Stony Brook, New York, and colleagues recently published a manuscript in Clinical Infectious Diseases that describes why it is important to include children in these trials.
Healio spoke with Nachman about the article and the issues it raised.
Question: Why are children being excluded from COVID-19 vaccine trials?
Answer: I think it started out with the overwhelming number of adults who were getting COVID-19, coming to the hospital and ultimately dying of COVID-19. I think that shook up the vaccine companies to say, “Oh, no, we've got to get a vaccine out for adults,” which was appropriate thinking at that time. Now that we're moving forward rapidly and vaccine products are being studied in phase 3 studies, it's important to look around now and say, “What about kids?” That idea that kids are sort of not getting sick, they're not getting infected and they're not passing COVID-19 on, is no longer true. We know that kids are getting infected, and we see them passing it — just go to any school, nowadays, you'll see that children are getting COVID-19. And they are passing it to other children. So, the idea that they're somehow exempt from this viral pathogen isn't true anymore.
Q: Does this mean children will be excluded from FDA approvals of COVID-19 vaccines?
A: I think that the first COVID-19 vaccines that will come, will have absolute indication for adults over 18 [years] and they won't have any approval for children. The problem is — how long do you wait before you also include children in studies? We don't feel it's appropriate to wait until a product is licensed and out there, because then it's just too late.
Q: Can study data on adult vaccination be extrapolated to estimate safety and efficacy in children?
A: No, you cannot. You probably can extrapolate some efficacy data, but it's going to be hard to extrapolate complete efficacy data, and certainly complete safety data.
Q: What kinds of studies are needed?
A: I think at first pass, we definitely need some phase 1 [and/or] 2 studies. We need to appreciate if that dose in children is too low or too high. There's lots of examples in the literature where children sometimes need a lower dose of a vaccine product to make the same immune response in adults, and that might be important. If it costs a certain amount of money to manufacture for an adult dose, maybe the cost will come down if you need less of a dose for children.
So, that's point one. Point two is that children often get other illnesses and other vaccines, and we need to make sure that there's no problems with giving them at the same time, near the same time, at different times or when you are seeing other illnesses and other viral pathogens. Those things need to be evaluated.
Q: Are children left out of research for other diseases?
A: Certainly. I believe that children are often second tier, third tier, when it comes to new investigational products, because we see the lag time from approval of a medication in adults; recognizing that sometimes kids don't need those drugs, and that's OK. But for those who do need it — new antibiotics, new antivirals, etc. — children often lag eight [or more] years behind adults. That's true in the antimicrobial world and the tuberculosis therapeutics, you name it.
Q: Anything else to add?
A: We're discussing adults, we're discussing children, but neither of us have talked about pregnant women. As you can imagine, all of the COVID-19 vaccine studies exclude pregnant women. So, as much as children are being excluded, we need to understand how we can vaccinate and when we should vaccinate pregnant women.