In late September, the Advisory Committee on Immunization Practices (ACIP) withdrew its endorsement of a combined measles-mumps-rubella-varicella (MMRV) vaccine, and on Oct. 6, the CDC formally endorsed the change. Its reason? The small but real increased risk of febrile seizures with the MMRV shot.
This decision highlights an uncomfortable tension that exists in the vaccine schedule: What happens when protecting children and treating them fairly are in conflict? For almost 20 years, children in the U.S. have been vaccinated against these four diseases in a two-dose series — the first dose is given to toddlers, the second right before kindergarten. But there has been a clear divide in how the first dose is given. Those with private insurance have received two shots — the separate MMR and varicella vaccines. Those on Medicaid have received the single MMRV shot.
The combined MMRV vaccine was licensed in the U.S. in 2005. Soon after its release, it was no longer recommended as a first-line option. Initially, this was due to shortages, but soon after the MMRV vaccine launch, the increased risk of febrile seizures became clear. While the risk was statistically small — one additional seizure for every 2,300 children vaccinated — it was enough for the CDC to say the combined shot should be used only if parents asked for it after a discussion of the increased risk.
This recommendation translated into about 85% of U.S. children getting the two separate shots and 15% getting the single shot. Who got the riskier single shot? While we don’t have a clean data set that provides a breakdown by income or insurance status, recent statements by leaders in the field strongly suggest that poor kids were the ones who got the combined MMRV vaccine.
What’s the evidence for this? Some ACIP committee members expressed concerns that changing the recommendation could lead to a lack of access for parents who preferred the combined shot. But “access” isn’t what limits options for families in private offices. It’s a Medicaid problem. The kind that shows up when a parent has to borrow a car, leave work early and hope the clinic still takes walk-ins at 4:30.
So when the committee spoke about “access,” they were saying the quiet part out loud — the kids who will be impacted by this change are poor kids because they are the ones who’ve been getting this shot.
That should make people uncomfortable. It defies credulity that this has been a parent-driven process, even though the single shot was only meant to be offered if the parent requested it. And this wasn’t an issue of cost. It was about administrative convenience and an assumption that poor parents would less reliably bring their children in for a second shot.
Administrative convenience isn’t a moral defense, having two different levels of risk tolerance, one for affluent children and one for poor. The risk was small, but it was doubled, and it landed disproportionately on families with the fewest choices.
I grew up on Medicaid, and most of my family still depends on it. “Access issues” are policy-speak for poor. It stings to know that there are public health leaders, however well-intentioned, who think that poor kids having more seizures than rich kids is a reasonable tradeoff for staying up to date with the schedule. No one says that directly, yet everyone sitting in the waiting room knows it.
The CDC’s new position, ending the combined MMRV vaccine for the first dose, finally brings policy for all kids in line with the standard of care affluent kids have received for almost 20 years. But if equity means anything, the agency owes the public more than a quiet revision of the schedule. It owes an explanation.
How did a system built to protect children decide that it was OK for poor children to have twice the risk of febrile seizures in the name of administrative convenience? And why did it take nearly 20 years to acknowledge it?
When I trained in public health, there was a phrase that was often repeated by my professors — every issue of public health is first and foremost an issue of social justice. By that standard, the history of how we handled the MMRV vaccine failed miserably. The CDC’s actions are an important step in correcting a well-intentioned wrong.