A new RSV shot could help protect babies this winter — if they can get it in time

Emily Bendt got excited when she first heard the Centers for Disease Control and Prevention had approved a new shot to protect infants from RSV.

That was back on August 3, when she was in the last trimester of pregnancy.

By October 5, she had given birth, and was cuddling with her new baby, Willow, on the couch at home in Vancouver, Washington.

But her excitement had turned into frustration. The new therapy, called Nirsevimab, had started shipping in September — but Bendt, a pediatric home health nurse, couldn't find it anywhere.

That very morning, at Willow's two-week check-up, Bendt had asked the pediatrician when Willow could get it. "She literally just shrugged and was like, well it's coming but we don't know when," Bendt says. "I don't know why I feel like I'm having to chase people down and still not get answers."

Bendt searched online too, for clinics or pharmacies or government websites offering Nirsevimab — and found nothing.

By mid-October, demand for Nirsevimab had already outstripped supply, according to the pharmaceutical company Sanofi.

In response, the CDC issued interim guidance Monday to help pediatricians allocate the limited supply of doses, advising them to focus on the infants at highest risk of RSV complications: babies under 6 months old, and those with underlying medical conditions.

RSV is the leading reason babies under 12 months end up in the hospital, and an estimated 100-300 infants die from it in the U.S. every year.

Nirsevimab, a monoclonal antibody, is actually one of two new therapies available this fall that could dramatically reduce the risk of lung infections for infants.

The other option is a new RSV vaccine from Pfizer. It was first recommended for adults 60 and older, and then on September 22, the CDC approved its use in pregnant people, too, as a way to confer immunity on their infants.

But this adult vaccine is only recommended during a relatively short window in pregnancy, weeks 32 through 36, due to a potential but unproven concern it may increase preterm births. That might limit uptake of the vaccine during pregnancy.

The CDC is now asking prenatal care providers to warn their patients about the potential Nirsevimab supply shortages, with the hope that driving up the maternal vaccination rate could help ease the demand for Nirsevimab.

The powerful potential promise of Nirsevimab

Supply is not the only challenge facing Nirsevimab. Pediatricians say its high cost, as well as bureaucratic obstacles in Medicaid's vaccine distribution system for children, are also slowing down Nirsevimab dissemination. They fear these problems leave infants at risk - unnecessarily - of hospitalization this winter.

In clinical trials, Nirsevimab reduced RSV hospitalizations and health care visits in infants by almost 80%.

"This is groundbreaking, honestly," says Dr. Katie Sharff, chief of infectious disease for Kaiser Permanente Northwest.

Nirsevimab is a monoclonal antibody treatment, not a traditional vaccine. The passive immunity it confers lasts about five months. But that's long enough to get babies through their first RSV season, when they're at highest risk for complications.

After an infant's first winter, "their airways develop and their lungs develop," Sharff says. "So getting RSV later, as a child instead of as an infant, [means the child is] probably less likely to have severe complications of difficulty breathing, needing to be on a ventilator."

Sharff's own daughter had an RSV infection as an infant, needed care in the emergency department, and went on to develop asthma, a condition that's more common in children that had severe RSV infections.

For health systems that have been worn down by the so-called "tripledemic" of respiratory viruses – Covid, flu and RSV – keeping infants out of the hospital this winter could be a game-changer.

U.S. health system was hit hard last winter by pediatric RSV

Last year was a historically bad season for RSV.

Earlier in the pandemic, measures that states took to slow the spread of COVID-19, such as masking, depressed RSV infections for a while, too.

But as infection-control measures were rolled back, more babies and toddlers were exposed to RSV for the first time, at the same time. The virus came roaring back. Serious RSV cases requiring pediatric hospitalization soared during the winter of 2022-2023.

In Oregon, the surge prompted Gov. Kate Brown to declare a public health emergency and forced local hospitals to add capacity to their pediatric ICUs. Some hospitals even had to send patients out of state.

"The promise of Nirsevimab is that should never, never happen again," says Dr. Ben Hoffman, professor of pediatrics at Oregon Health & Science University's Doernbecher Children's Hospital, and president-elect of the American Academy of Pediatrics.

Nirsevimab is approved for all infants up to 8 months old, and for some older babies and toddlers considered at higher risk due to RSV. The American Academy of Pediatrics recommends that every baby whose mother did not get the RSV vaccine while pregnant receive Nirsevimab in the first week of life.

Where should newborns get the shot?

Except for the first dose of the hepatitis B vaccine, the standard childhood vaccines start being given one month after birth, in the pediatrician's office.

Nirsevimab could be given in hospitals, before newborns go home. Or pediatricians could give it at a baby's first office visit, but that can occur two weeks after birth, or even later.

It's unclear what clinical location will ultimately become the standard place where infants receive this shot in the U.S., or even if the shot will become standard for newborns. (That depends on whether the maternal RSV vaccine becomes a standard part of pregnancy care in the U.S.)

But what is clear is that neither pediatricians nor hospitals have become the go-to source for Nirsevimab this year, leaving many parents confused about where to find the shot.

One major issue is the initial price: at $495 per dose, it's the most expensive standard childhood shot. Many pediatricians have been reluctant to order it, unsure about whether they'll be reimbursed by insurers.

Because of a quirk in the Affordable Care Act, commercial insurance plans can wait up to a year before they are required to cover it.

"When all of a sudden you have a new product that you're supposed to give to your in entire birth cohort, and you've got to pay $500 that may or may not get paid back, that's just not financially viable, says Dr. Sean O'Leary, a pediatric infectious disease specialist at the University of Colorado School of Medicine.

Some insurers have announced they will cover Nirsevimab right away, but not all.

Sanofi has announced an order-now, pay later option for doctors, which would give them more time to work out reimbursement deals.

Could hospitals step in and help administer Nirsevimab earlier?

Even when cost is not an issue, problems remain. A government program that supplies free shots to about half of the children in the United States is structured in a way that makes it hard to give Nirsevimab to newborns right after birth.

The program, Vaccines for Children, is a safety-net program that provides vaccines to children on Medicaid, uninsured children, and Alaska Native and American Indian children.

Health care providers can't bill Medicaid for shots like Nirsevimab. Instead, they have to register and enroll in the VFC program. Through it, the federal government purchases shots from companies like Sanofi at a discount, and then arranges for them to be shipped for free to VFC-enrolled providers, which tend to be pediatric practices or safety-net clinics.

But most hospitals aren't part of VFC, which presents a problem. Pediatricians say the fastest, fairest way to get Nirsevimab to as many families as possible, is to offer it just after birth, before families leave the hospital.

"Many of our newborns go home to caring, affectionate, loving siblings who are actively dripping snot at the time that the child is born," says Dr. Eddie Frothingham, a pediatrician with Mid Valley Children's Clinic in Albany, Oregon. "The sooner we can protect them, the better."

Right now, only about 10 percent of birthing hospitals nationwide are enrolled in VFC and can get Nirsevimab for free.

In Oregon, out of more than 40 hospitals that deliver babies, just one is enrolled in VFC.

Nirsevimab highlights problems with Vaccines for Children

Until Nirsevimab's debut a few months ago, most hospitals didn't have a strong incentive to participate in Vaccines for Children. The rest of the childhood vaccine series is typically given to kids by pediatricians, in outpatient clinics.

The VFC program can be burdensome and bureaucratic, according to interviews with several Oregon hospitals and immunization experts. The program's stringent anti-fraud measures discourage health care providers from enrolling, they say.

Once enrolled, providers have to track and store VFC-provided vaccines separately, apart from their other vaccine supplies. The person giving a pediatric shot has to know what insurance the child has, and account for each dose in a state-run electronic record system.

Mimi Luther, the immunization program manager for the state of Oregon, says the rules are nearly impossible for most hospitals to follow.

"I look forward to the day when the feds have the opportunity to modernize that system to make it easier for providers to enroll and stay enrolled," she says.

The CDC has relaxed some program rules in light of the shortage of Nirsevimab, allowing providers to "borrow" up to 5 VFC doses for infants covered by private insurance - so long as those doses are paid back within a month.

For now, Nirsevimab is reaching patients in various ways, and many infants aren't getting it as soon as recommended.

This has forced some hospital systems to make difficult choices. Many are allowing infants to leave the hospital without the shot, assuming they will get it at the first pediatric outpatient visit.

Frothingham says that also creates an equity problem. Newborns whose parents don't have transportation, or financial resources, are more likely to miss those first pediatric appointments after birth.

Samaritan Health Services, the health system Frothingham works for, has decided to privately purchase a small number of doses to offer in its hospitals, for newborns whom doctors flag as high risk, due to breathing problems or family poverty.

"It's important to us that infants be able to access this regardless of their financial or social circumstances," Frothingham says.

Nationwide, many birthing hospitals are trying to enroll in the VFC program for next year. But this fall, most hospitals won't have free Nirsevimab on hand.

Most babies who get RSV ultimately recover, including those who require hospitalization to help with their breathing. But it's challenging to treat, and it does kill an estimated 100-300 children every year.

In his decades in medicine, OHSU's Hoffman has lost infant patients to RSV.

"Knowing that some kids may potentially suffer because of delayed access or absence of access to a product that could potentially save their lives is awful," Hoffman says. "No pediatrician in the country is happy right now."

This story comes from NPR's health reporting partnership with Oregon Public Broadcasting and KFF Health News.