A Pediatrician's Perspective on ACIP’s Childhood Vaccine Recommendations

Sharon Nachman, MD

Image credit: Stony Brook

This past week, the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) had a 2-day meeting to discuss the measles, mumps, rubella, and the varicella (MMRV) vaccines, the hepatitis B vaccines, and COVID-19 vaccines.

The committee voted to restrict the combined MMRV vaccine to only children 4 years and older. They recommended children younger than this age group to receive separate MMR and varicella vaccines. Their justification was given largely due to reducing the risk of febrile seizures.

They decided to table their vote on whether to recommend a change to the hepatitis B (HBV) immunization schedule for neonates from its current date of birth timeline and move it back to 30 days after birth. The committee also voted unanimously, (12-0), to recommend all women get tested for hepatitis B infection. Before this vote, this was already in place. CDC had previously recommended all pregnant patients be screened for HBV.¹

Sharon Nachman, MD, chief of pediatric infectious diseases at Stony Brook Children's Hospital, sat down to talk with Contagion about the MMRV and hepatitis B vaccines and what parents, other providers, and public health officials should know about the ACIP’s recommendations and existing clinical practice.

Contagion: For those not familiar with current guidance regarding the MMR and MMRV vaccines for children 12-17 months, can you provide an overview of what the recommendations are in this age group?

Nachman: Up until now, the MMR or MMRV were both available to parents, and parents had the choice until now to either get the single dose MMRV or to get 2 shots—the MMR vaccine in one thigh and varicella vaccine on the other side. And what the ACIP has done is taken away from parents, the choice to get the single shot of MMRV, and recommended only the MMR as a single dose and the varicella as a second single shot. This translates into children will get 2 vaccines at the same time and not 1 vaccine shot at that time.

With regard to age 4, they have continued the current recommendation, which allows MMRV to be given as a single dose vaccine. So there is no change in the recommendation that children at 1 year of age should still get measles, mumps, rubella, varicella vaccinations. The only change is that instead of giving it as a single-dose shot, they're going to have to get it as 2 independent-dose shots.

Contagion: ACIP recommended against using the combined MMRV vaccine before age four, they say, largely due to febrile seizure risks. How significant is this risk compared to the benefits of these combination vaccines?

Nachman: So febrile seizures occur between 3% and 5% of all children around the world. They are short term they do not have any long-term consequences. And interestingly enough, children that get febrile seizures often get them when their fever curve changes, either rapidly goes up or rapidly comes down. So that means that those children who may or may not have gotten it from a vaccine, they actually will go out and get some viral illness and have a febrile seizure from that.

Because we have so much data on febrile seizures, we can tell parents they are short, they are not long term, they do not require lifelong medications, and more importantly, the children outgrow them with no lasting consequences. So the concern from ACIP with regard to the very small incidence of febrile seizures associated with the vaccine does not change the course of febrile seizures in those children, because if they've had it from that vaccine, they are also highly likely to have it from any other viral illness that causes a rapid change in their fever at those age groups as well. So yes, the vaccine was associated with a small percentage of children getting febrile seizures. But in the big scheme of things, febrile seizures are benign. They will still occur.

We will still consult with parents regarding febrile seizures, and we will still not treat them. Those febrile seizures associated with the vaccine, in no way say that the vaccine was not effective, or the child is contagious from those viruses, or anything like that, because it occurs within 24 hours of getting the vaccine, because of the fever associated from your immune system, waking up and starting to make an immune response to the viruses to the vaccine that you were given. So that virus, those vaccines, are still going to be given. There is no recommendation from ACIP to not give those vaccines at that age group, and we should still expect children to get those vaccines because they are safe.

Contagion: And just to clarify, the 3% to 5% statistic that you mentioned, is that the overall number with the side effects from the vaccine, or is that just the number of overall seizures that kids have no matter if they have had the vaccine or not?

Nachman: That number represents the annual number of kids; the incidence of febrile seizures in children. And it can be a little higher or lower in some families. So if your first child had febrile seizures, we're often not surprised to see that your second child will also have febrile seizures. But as I've said, these are benign, they are not lifelong, and we do not treat them with any anticonvulsant medications, because they are benign and they go away.

Contagion: Some ACIP panelists questioned the rationale for delaying the hepatitis B vaccine to 30 days especially with strong safety data supporting at-birth dosing. Do you think the current immunization schedule of administering the vaccine on the day of birth is beneficial?

Nachman: So there is incredibly strong data that administering the dose at birth saves lives. That's number one. Number two, this idea that we will be able to test every pregnant women at the time of delivery for hepatitis B infection is quite faulty. Women that enter medical care when they're pregnant get tested often, that is early in their pregnancy, so we have zero ability to retest any of those who tested negative in the past at the time of delivery. we said, oh, if you're negative, then you're probably negative. Now that's clearly not true.

The second is, we often have many women who don't come into care early, or because of insurance issues, don't get the testing performed. That means at the time of delivery, they have no test results. In an acute emergency, it is possible, on occasion, to test someone for hepatitis B infection at the time of delivery. that requires a technician be available, have the appropriate testing things in the lab, and be able to run the test—and that's labor intensive.

If you take a routine hospital such as ours here in Long Island, with about 4500 deliveries per year, and assume that we're only going to miss about 10% 20% of them having results. That is a huge amount of women delivering every day without results. We don't have technician support to run hepatitis B testing on all of them. Thus, the move to giving hepatitis B vaccine to infants at the time of delivery or post delivery saves those infants lives. Because, as you know, getting hepatitis B infection at a very young age puts you at a chronic hepatitis B infection disease, which we often cannot treat. More importantly, it causes cirrhosis of the liver and leads to early death, and we can't fix that. So the idea that we would put off the birth dose of hepatitis B vaccine to 1 month means that we may still see some fever, fussiness, irritability in those babies, and we would lose the ability to prevent hepatitis B infection in those very same infants. So there is only loss, and no gain, by putting it off for a month.

Contagion: How are you interpreting the ACIP’s decisions around childhood vaccines thus far?

Nachman: I think that they are very passionate about what they're looking for. They're looking to be able to give the American public what they feel is information that is lacking; however, the lack of anyone on the ACIP who's actually run or written clinical trials in children understands what is related to vaccination, not related to vaccination, or even the output of the data from those vaccine trials, makes them at risk for, I want to say, secondhand interpretation of the data, as opposed to they understand what went into the clinical trial and how to read the results themselves.

That leads to significant possibilities of misinterpretation. It's like picking up a spoon. I could pick it up by the handle or the rounded edge, and depending on which edge of the spoon I pick up, I get a very different answer. But, if you looked at the spoon as a whole, you could say, here's where I hold it, here's where I feed myself, and here's where something may fall off the spoon.

Contagion: Are there any other important takeaways around childhood vaccines?

Nachman: So, I think the American public does need to hear the data on those vaccines, but they need to hear it from a trusted source. Who is that trusted source? Often it is someone who's actually in the mix. They understand why the vaccine study was done, what the pros and cons of it are, what it can say and it cannot say, and what it means for their particular child.

I do want to confirm that at this point, any baby that gets a hepatitis B vaccine in the US, it is with consent of the mother. We're not running around and giving vaccines to babies unbeknownst and approved by the parent. Before we give any shot to an infant, even at birth, we always ask the parent, 'is this okay?' No one sneaks around and gives vaccines without the parent knowing. So one of the ACIP talking points was equity of having the parents agree for the vaccine. I want to say, well, that was nice that ACIP pointed it out. It's actually standard practice right now.

Reference
1.Clinical Guidance for Perinatal Hepatitis B Testing. CDC. January 31, 2025. Accessed September 19, 2025.
https://www.cdc.gov/hepatitis-b/hcp/perinatal-provider-overview/clinical-testing-guidelines.html