A talk with Dr. Jeffrey Gerber on the COVID-19 vaccine for children under 12

Jeffrey S. Gerber, MD, PhD, is an attending physician in the Division of Infectious Diseases at Children's Hospital of Philadelphia, Medical Director of the Antimicrobial Stewardship Program, and Senior Scholar within the Penn Center for Clinical Epidemiology and Biostatistics. Contemporary Pediatrics® recently spoke with him about the status of COVID-19 vaccines for children aged 12 and younger.

Q: COVID vaccines are now happening for children aged 12 and over. What do you anticipate will be timeline for younger children to get the vaccine?
A: Everything is speculation. The companies set the timelines, obviously. Things can happen, we know from the Johnson & Johnson story, an adverse effect happened and they had to pause trials. That said, in the United States, the 2 leading the way are with messenger RNA (mRNA), so Pfizer and Moderna have started putting together trials for young children down to infants aged 6 months. They are in the thick of testing those age groups. I know, with Moderna, they get broken down into subgroups, such as those aged 5 to 11, 2 to 5 then 6 months to under age 2.

These trials are combining phases 2 and 3, so they are dose-finding with age
deescalation. It moves in that cadence. They are really focused on safety. The randomized control trials can also be separated by age. That creates a tiered approach to timing. Roughly, both companies hope to have data on children aged 6 to 11 in the fall, September or October. There has been overwhelming interest from parents and children for subject enrollment. But then the US Food and Drug Aministration (FDA) has to decide whether to do an emergency use authorization (EUA), and, if so, will they require 2 months of data, more, etc. Or, if they don’t even do an EUA it will take several, as opposed to a couple of months, to bring to market. Midfall you might see emergency use. The first cohort of kids won’t become immune (fully vaccinated) to end of year, at best.

Q: Any other pediatric vaccinations to talk about for the coming fall season?
Other than the new flu vaccine, and we have already made recommendations for that, it really is the COVID-19 vaccine we are watching for. The rabies vaccine is being tweaked a bit. Otherwise, it is trying for the big things, getting kids up to speed with all the vaccinations they missed. One major piece of collateral damage from the pandemic has been kids not going to their doctors to get their vaccines.

Q: Do you have a wish list for infectious disease (ID) vaccines you’d like to see researchers start trials for?
Pie in the sky wish list? The HIV vaccine: people have been working on that for a long time. Acute respiratory viruses: a vaccine for respiratory syncytial virus (RSV) is one that would change pediatric care immensely. I do a lot of my inpatient work in immune-compromised hosts so a cytomegalovirus virus would be revolutionary . Adenovirus can have devastating effects; Epstein-Barr can wreak havoc on transplant patients.

With all this new mRNA based technology, you can see companies like Moderna have candidates for those vaccines they are trying to move. That platform will hopefully translate to tackling these really common infections that can cause a lot of harm to kids.

Q: How much of an impact has mRNA had for the future of vaccinology?
It has clearly made a massive imprint on this pandemic. It has been incredible. both in terms of speed and its protection and safety; in these ways, it is not surpassed by very many vaccines. They have been scrutinized and scrutinized and really held up. And companies like Moderna and Pfizer have been able to pivot and change the sequence to create variant vaccine boosters. To be nimble that way is a huge plus. I think the immunogenicity and safety will hopefully translate to other vaccines.