After last year’s record-breaking season for respiratory syncytial virus, or RSV, that saw hospital beds packed with kids, pediatric health care providers and parents were elated to hear that a once-per-season RSV vaccine was approved by the Food and Drug Administration for babies and moms-to-be over the summer.

“Everyone in primary care, pediatrics, we were so excited,” said Dr. Theresa Nguyen, chair of the department of pediatrics at Greater Baltimore Medical Center HealthCare. The vaccine, which the Centers for Disease Control and Prevention recommends during respiratory virus season for babies from birth up to 8 months — or up to 19 months for those with certain health issues — protects infants and toddlers from severe disease and could also spare the health care system from being crushed by yet another record-breaking respiratory virus season.

Then, nothing happened.

It was mid-November before Nguyen’s practice, GBMC Pediatric Group, finally got a vaccine shipment — roughly two-dozen doses for babies under 11 pounds, and none for larger babies. The hospital, which Nguyen said has the largest volume of births in the Baltimore area, received even fewer doses to give to newborns. Her practice expects to receive a second vaccine shipment of the same size next week, and “that’s it for the season,” she said.

“It’s a huge problem right now,” Nguyen said. “No one’s getting it in Maryland.”

No one’s getting much anywhere, according the CDC, which released guidance last month instructing providers on how to prioritize the few doses they have, with future supplies still unknown. Meanwhile, cases are surging in the Southern U.S. and Maryland is now firmly in RSV season, with an early spike in late October and more certain to come as holiday gatherings commence.

Here’s what to know about the shortage.

What is RSV, and why is it worse for babies?

RSV is a common seasonal respiratory virus with potential to cause severe illness in children, particularly those under 3, as well as older adults and pregnant people. For the average adult or older child, RSV feels like the common cold, causing congestion, cough and sometimes sore throat, fever or headache.

Children under 1 year old are most susceptible to severe RSV because their lungs are less developed and can’t handle large volumes of mucus while breathing and consuming water and food, Nguyen said. The younger the infant, the higher the risk — babies under 6 months or with underlying conditions are even more vulnerable, she said, and those under 3 months are most likely to be hospitalized with the virus, according to the CDC. About 58,000 children under 5 are hospitalized from RSV in the U.S. each year, and up to 300 die.

Last October, Maryland’s RSV hospitalizations skyrocketed from 33 to 263 as the virus spread among babies and toddlers months earlier and in much greater numbers than what was typical pre-pandemic.

The most at-risk infants are those born prematurely. They can receive a preventive monoclonal antibody treatment, given monthly by injection, that’s been used widely in preemies since the late 1990s. They’re also eligible for the new RSV vaccine.

What is the new RSV vaccine for babies, and how does it work?

The new RSV vaccine — sold under the drug name nirsevimab and brand Beyfortus — is a long-acting monoclonal antibody that protects babies from the kind of severe illness that could land them in the hospital. It’s a seasonal one-and-done shot that could minimize clinic visits — and resulting exposure to illness — for highly vulnerable preemies.

Now, with current paltry supplies, premature infants will continue to receive the once-monthly medication during RSV season, Nguyen said. Priced at $2,000 per shot, it’s significantly more expensive than the vaccine, which costs $500.

Although private insurers will have to cover the new vaccine since it will be on the U.S. Preventive Services Task Force list, they’re given a year to do so — starting from when the CDC recommended the shot in August.

The vaccine remains unavailable for all but the highest-risk infants — such as those being discharged from the neonatal intensive care unit — who will be prioritized to receive the precious few doses providers have.

What can parents do to protect children from RSV if vaccines aren’t available?

The last and best line of defense is for pregnant people to get vaccinated against RSV, Nguyen said, as doing so will protect them as well as their baby. A seasonal RSV vaccine for adults aged 60 and over as well as those who are pregnant was recently FDA approved and has not been in short supply.

The CDC recommends women between 32 and 36 weeks of gestation get the shot, as this allows sufficient time for the fetus to produce antibodies against the virus before birth. Infants with vaccinated moms do not need to get the shot themselves, Nguyen said.

Pregnant people should first check to make sure their pharmacy has the vaccine, then ask their obstetrician or prenatal provider to send in a prescription, Nguyen said. Alternatively, patients can ask for a paper prescription at a visit and take it with them to a pharmacy.

Not all pharmacies will have the vaccine, Nguyen said, so it’s important to check first. CVS and Walgreen’s, for example, offer online appointment scheduling for pregnant people and older adults in need of the RSV vaccine.

Otherwise, “we’re stuck in our traditional advice that we can offer” to protect babies and young kids from RSV, like “really good hand washing,” said Dr. Rebecca Carter, division head of general pediatrics at University of Maryland Medicine. Like GBMC, her practice has also received one very small shipment of the vaccine for smaller babies, with an even more limited supply of the larger dose.

“If somebody is sick, they really shouldn’t be around a young infant,” Carter said.

People with cold symptoms should wear masks in public spaces, Nguyen said.

Keeping up on other seasonal vaccines, such as those for flu and COVID-19, will help prevent other severe respiratory illnesses and alleviate some of the burden on the health care system, Carter said. That will make it easier for people to access health care they might need, such as their child’s pediatrician or the emergency department.

What’s causing the shortage?

A spokesperson for the vaccine’s manufacturer, Sanofi, said in an email that demand for the vaccine has been “unprecedented” and “despite an aggressive supply plan built to outperform past pediatric immunization launches,” the company hasn’t been able to keep up.

The CDC and FDA recently announced they would ship an additional 77,000 doses of the vaccines for infants over 11 pounds, and the agencies “will continue to be in close contact with manufacturers to ensure the availability of additional doses through the end of this year and for early 2024 to meet the demand,” the agencies said in a news release.

Some of the 77,000 new doses were paid for by the federal Vaccines for Children program, and they’ll be earmarked for uninsured kids or those with Medicaid.

Nguyen said the majority of the vaccines GBMC has received so far and all of those expected in the next scheduled shipment have come from the Vaccines for Children program and can only be given to certain kids.

She said this is the first time publicly funded vaccines have arrived before the private supply.

Of the 77,000 additional doses, the supply available to privately insured kids will be “limited,” the Sanofi spokesperson said. The company will “continue to update providers in the private market about the status of their orders and any potential availability of additional doses for shipment.”

In the meantime, Carter said health care providers are “prepared and planning for potentially a lot of kids infected with RSV over the season.”

“Unfortunately, it’s looking very unlikely that we’ll be able to cover the vast majority of babies born this year,” she said.

sarah.true@thebaltimorebanner.com