The ability to inoculate young children against COVID-19 in the U.S. may be diminished this fall as the FDA weighs whether to renew the emergency green light for the vaccine currently cleared in the broadest group of kids.

“The FDA has communicated to Pfizer the intent to potentially not renew emergency use authorization for the Pfizer-BioNTech COVID-19 vaccine for individuals aged 6 months through 4 years,” a Pfizer spokesperson told Fierce Pharma over email.

The company is in talks with the regulator about a path forward for its pediatric vaccine and has asked that the emergency use authorization (EUA) in kids under 5 years stay in place for the 2025-26 season, the spokesperson added.

“It is important to note that these deliberations are not related to the safety and efficacy of the vaccine which continues to demonstrate a favorable profile,” the spokesperson continued.

Given the potential change to the pediatric vaccine landscape for COVID-19, Moderna is reportedly working with the U.S. Centers for Disease Control and Prevention (CDC) to step up supplies of its own mRNA-based shot for COVID prevention in kids, The Guardian first reported.

The CDC is in discussions with Moderna to rapidly increase its pediatric COVID vaccine supply, working through considerations like volume, shipment timing and potential supply gaps, The Guardian reported, citing information gleaned from an email sent out by the CDC’s National Center for Immunization and Respiratory Diseases last week.

A Moderna spokesperson told Fierce Pharma over email that it anticipates being able to step up supplies of its vaccine. 

Crucially, Moderna’s shot is approved for use in people between 6 months and 64 years of age, but only in those with one or more health conditions that puts them at increased risk of COVID-19. The vaccine is also approved in all people ages 65 and older.

Pfizer’s pediatric EUA does not come with the same stipulation concerning recipients' underlying health conditions.

“The COVID-19 pandemic ended with the expiration of the federal public health emergency in May 2023,” said a spokesperson for the Department of Health and Human Services (HHS), which oversees the FDA.

“We do not comment on potential, future regulatory changes,” he said. “Unless officially announced by HHS, discussion about future agency action should be regarded as pure speculation.”

The potential change coincides with various actions under Robert F. Kennedy Jr.’s HHS that some industry watchers have taken as a sign of growing anti-vaccine sentiment within the U.S. federal health apparatus.

Back in May, FDA Commissioner Marty Makary, M.D., and Center for Biologics Evaluation and Research chief Vinay Prasad, M.D., laid out a new “evidence-based approach to COVID-19 vaccination” that proposed stricter requirements for future COVID shot approvals.

Shortly after that, the CDC overhauled its vaccine recommendations in COVID, nixing its endorsement of the shots for pregnant women and healthy children. At the time, RFK Jr. said he “couldn’t be more pleased” about the decision and cited a lack of “clinical data to support the repeat booster strategy in children.”

If the FDA chooses not to renew Pfizer’s pediatric vaccine EUA, the shots available for young kids will be more limited in the U.S. Aside from the limitations on Moderna’s pediatric label, Novavax’s protein-based COVID-19 vaccine is only approved in people ages 12 and older. Pfizer and BioNTech's vaccine carries a full approval for use in people 12 and older, too.