Should babies get a 'bonus dose' of the measles vaccine? Doctors say it depends

Yahoo

06-03-2025

Like many anxious parents, Beth Spektor spent the last few weeks fretting over how to protect her infant daughter from the first deadly measles outbreak to hit the U.S. in a decade.
Her 9-month-old was too young for the first dose of the measles, mumps and rubella vaccine, typically given to American toddlers shortly after their first birthday.
But when her New Jersey mommy WhatsApp group started buzzing about an early bonus dose of MMR for babies, Spektor decided to ask her pediatrician for one anyway.
"I was assuming she would say, 'It's up to you,' or 'It's not a bad idea,' something a little less definitive," the mother said.
Instead, the doctor urged her to take the extra jab, a move they recommended to all infant patients after three linked cases were reported in their region.
"[The doctor] said she was hoping that [U.S. Secretary of Health and Human Services Robert F. Kennedy Jr.] would change the schedule to recommend that all babies over 6 months get the bonus dose," Spektor said.
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That's unlikely, experts say. Despite the current outbreak, measles is still rare in the U.S., and while MMR is safe for babies as young as 6 months, it's more effective in toddlers. Most pediatricians still recommend holding off until a child's first birthday, with few narrow exceptions.
Meanwhile, Kennedy has spent this week touting codliver oil and steriods, alongside a tepid endorsement of vaccines.
Yet even as record numbers of parents now delay or decline inoculation, pediatricians and public health experts said they've seen a surge in requests for bonus doses following the death of an unvaccinated six-year-old in West Texas last week.
When reports of an infected Orange County infant carrying measles through Los Angeles International Airport began to circulate Friday, that curiosity turn to panic in some households.
"There has been a noticeable increase in parental concern about measles, particularly among those who plan to travel with young children or who have infants in daycare," said Dr. Priya R. Soni of Cedars Sinai Medical Center, an assistant professor of pediatric infectious diseases. "Some parents are requesting early MMR vaccination, which is an appropriate strategy in certain high-risk situations."
So-called "zero" or "supplemental" doses of MMR have long been recommended to jet-setting infants who will travel to countries such as Ireland, Sri Lanka or the Philippines before their first birthday.
While most people survive a measles infection, the disease kills more than 100,000 children every year worldwide, leaves an additional 60,000 children blind and thousands more with permanent brain damage.
The grave risks are why early shots are also given to babies living near domestic outbreaks. The Texas Department of Public Health is currently recommending bonus doses for infants in six counties, including Gaines, where the largest outbreak emerged.
"It's one of the most contagious illnesses that we know about," said Dr. Meghan Martin, a pediatric emergency medicine doctor at Johns Hopkins All Children's Hospital in St. Petersburg, Fla., who helps explain infectious disease to her 2.3 million followers on TikTok.
Martin got her own daughter a bonus dose before a visit to New York during a measles outbreak there in 2018. But she said most parents should forego it unless their babies are headed to a high-risk country or live in an outbreak region.
Dr. Eric Ball, a pediatrician in Orange County and chair of the American Academy of Pediatrics' California chapter, said he recommended bonus doses to his patients in 2014, during the height of the Disneyland outbreak. But with no active outbreak in the area, he is advising patients to wait.
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But some doctors said they were open to early vaccinations even for infants whose daycare classmates travel abroad, as well as families in communities where many parents avoid or space out vaccines.
"I actually recently had a conversation with a parent [who said], 'We're moving our almost one-year-old to a place with a lot of vaccine hesitancy, so we'd like to do an early MMR,'" said Dr. Nelson Branco, an assistant clinical professor of pediatrics at UCSF, who sees patients in Marin County. After searching the local kindergarten vaccination rate, "I said, 'It's not strictly recommended, but I would give it if you'd like.'"
Doctors agree early jabs aren't as effective as later ones, which is why they don't count toward the two-dose series all children need for kindergarten.
That hasn't deterred some pro-inoculation parents on TikTok and Reddit from trading tips on how to snag extra shots for trips to Disney World, even as anti-vax parents smear them as toxic and deadly on the same comment threads.
"Looking through posts [on Reddit], I kept seeing it," said Angela Owens, a first-time mom in Maryland who underwent a stem cell transplant in 2022 and had not yet gotten a replacement MMR when she got pregnant. 'Continually seeing those posts, it's like, 'Am I worried enough? Am I worried too much?''
Doctors said their experience was the same in clinic.
"I'll be in one room, and I'll talk to a patient for 30 minutes to convince him to get one vaccine, and I'll go to the next room and have someone who is eager to give their kids an extra bonus vaccine,' said Ball, the Orange County pediatrician.
The practice of handing out bonus doses gave some experts pause.
Dr. Paul Offit, a pediatrician and director of the Vaccine Education Center at Children's Hospital of Philadelphia, said it reminded him of the early days of the COVID vaccine, with part of country refusing vaccination and part of the country collecting so many shots they "should have had a Pfizer loyalty card.'
"The benefits of waiting until 12 months of age is greater than the largely theoretical risk that you're going to be exposed to someone with measles," even in a daycare setting where a baby might be exposed to other children who are traveling internationally, he said.
Babies get their earliest "vaccines" from their mothers, in the form of blood proteins that pass through the placenta in the third trimester. Those maternal antibodies protect infants while their immune system matures. But they can also blunt the affect of the measles vaccine, neutralizing the weakened virus before the baby's body mounts a response.
"There's not a simple formula," said Dr. William Moss, executive director of the International Vaccine Access Center at Johns Hopkins. "If you wait longer, a higher proportion of children will develop a protective response. We're weighing that with the child's risk of getting measles."
In places where measles is common, the World Health Organization recommends the first vaccine at 9 months, when the vast majority of infants will develop immunity. Where it is rare, the recommendation is between 12 and 15 months when nearly all children will.
"There were some very early studies ... that did suggest children who got an early first dose of the measles vaccine had less of a response to a later dose," Moss said. "My take on that literature is it was flawed and there were a number of subsequent studies that did not demonstrate that."
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But newer studies have complicated the picture in another way, he said.
The current guidelines were developed at a time when many mothers had immunity from measles infections. Now, most have immunity from the vaccines themselves. Though babies still inherit these maternal measles antibodies, they're weaker and wane sooner than those from wild-type measles, studies show.
The World Health Organization has supported earlier inoculations in some cases, noting in 2020 that babies in countries such as the U.S. "may become susceptible to measles well before the age of vaccination, but they may also be more likely to develop protective immune responses when vaccinated."
Babies often get measles from school-age siblings, meaning as vaccine hesitancy spreads — including the practice of spacing or delaying vaccines — so does danger.
"We're seeing a lot more kids in practice that are not being vaccinated," said Martin, the Florida doctor. "Maybe only 85% of [2-year-olds] I see in practice are vaccinated, which is concerning."
She and other experts agreed, the best defense for babies is for everyone else to get their shots on time.
"The bottom line message is people should be vaccinated," Moss said. "If enough of the general population is vaccinated, we will protect infants from getting measles through herd immunity. That's what's worked."
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This story originally appeared in Los Angeles Times.