New R.S.V. Vaccines Had Limited Takers Last Year. Will This Year Be Better?

Some of the problems that patients ran into, including a lack of insurance coverage, have been resolved.

When the Food and Drug Administration approved several new vaccines against respiratory syncytial virus last year, the shots were celebrated as a “powerful new tool” to protect infants and older people. Pharmaceutical giants projected billions of dollars in sales, assuming a large swath of the eligible population would roll up their sleeves.

But for all the anticipation, relatively few people sought the vaccines out: Only about 24 percent of eligible older adults received it last season. It was a disappointing response, one experts blamed largely on vaccine fatigue, the cost of the shots and confusion over who should get them.

This season, however, promises to be different. Drugmakers have ramped up manufacturing of a treatment for infants that was in short supply last year, and more insurers are now covering R.S.V. shots. But experts said there are still hurdles that must be overcome to increase vaccination rates, including sharpening public health messaging and increasing the public’s understanding of how serious the virus can be for certain groups.

The Risks of R.S.V.

Most people with R.S.V. only experience mild symptoms, like a runny nose or a cough. However, for infants and older adults, especially those who are immunocompromised or have chronic conditions like heart or lung disease, a bout of R.S.V. can be serious.

There are up to 160,000 hospitalizations and 10,000 deaths from R.S.V. among older adults in the United States each year, according to the Centers for Disease Control and Prevention.

The virus is the leading cause of hospitalization in infants in their first year of life. Babies with R.S.V. can develop pneumonia and often need treatment with oxygen, IV fluids and mechanical ventilation to support their breathing. The virus can also be dangerous to some young children: Between 100 and 300 children under age 5 die each year of R.S.V.

The new shots can protect these high-risk groups. They include one-time vaccines for older adults and a maternal vaccine given in the third trimester to pass immunity on to newborns. There is also an antibody shot for infants under 8 months old who weren’t protected by the maternal vaccine, or babies from 8 to 19 months old who are at high risk of a severe infection.

Overcoming Last Season’s Obstacles

Last season, the C.D.C. said that people age 60 or older could get an R.S.V. vaccine, but should first consult with their doctor about whether to do so. That guidance caused confusion about how necessary the vaccines were, and for whom, experts said. The price was also a barrier: Because they were new, the vaccines weren’t yet covered by many insurance plans, which meant they could cost patients up to $300.

Doctors and pharmacists told the C.D.C. that they were hard-pressed to recommend a pricey new vaccine to older patients when the agency’s guidance didn’t make clear they needed it.

“They’d prefer, ‘just tell me to give it or not.’ Make it easy,’” said Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center who works with the C.D.C.’s vaccine advisory committee.

This season, the agency has clarified its guidance: Everyone over age 75 should be vaccinated, as should people who are 60 or older with certain serious chronic conditions or who live in a nursing home.

“If they’re less healthy and older, that’s when you want to spend that nickel,” said Dr. Camille Kotton, an infectious disease specialist at Massachusetts General Hospital and a member of the C.D.C.’s vaccine advisory committee. Medicare, Medicaid and private insurers are now required to cover vaccination for eligible groups.

Experts are also hopeful that the challenges that affected uptake among pregnant women and infants have been resolved.

Dr. Brenna Hughes, an obstetrician at Duke University Hospital, said many of her pregnant patients were interested in vaccination last season. But at about $300 a dose, and with insurers not yet required to cover the shot, it was out of reach for many of them.

“It was essentially impossible for them to access this vaccine,” she said. Just under a third of eligible pregnant women received shots last season, according to data released by the C.D.C. this week.

There was also significant demand for nirsevimab, the antibody drug for infants. But the treatment was in shortage for months. Parents scrambled to find doses. With a limited supply, the C.D.C. recommended prioritizing the highest-risk babies. The agency said that only about 45 percent of eligible infants received the drug by last April.

Nirsevimab’s maker, Sanofi, has said it will be able to produce far more doses this season. Infants will continue to be able to get the shots for free with insurance or through a federal program that pays for childhood vaccines. Most insurers will also now cover the maternal vaccine.

If more people got vaccinated this time around, the effects could be felt immediately, said Dr. Sean O’Leary, the vice chair of the American Association of Pediatricians’ infectious disease committee.

“If we had super uptake this year, we could see a huge drop in infant hospitalizations,” he said.