The Food and Drug Administration approved the drug, called nirsevimab, in July, making it the first preventive antibody treatment widely available to protect healthy infants against respiratory syncytial virus, the No. 1 cause of infant hospitalization in the United States. But demand for the RSV treatment has vastly surpassed the supply.
“It has been very frustrating for parents and pediatricians alike to know that this treatment option is out there, but not available,” said Krupa Playforth, a pediatrician based in Virginia. “Pediatricians are stuck with limited doses, and having to figure out how to ration them — and to field calls from frustrated parents — has been especially challenging.”
The CDC said the additional 100 milligram doses of nirsevimab will be distributed immediately to hospitals and physicians through the federally funded Vaccines for Children Program and commercial payers.
“CDC and FDA are committed to expanding access to this important immunization so that more parents have peace of mind during the winter virus season,” Nirav D. Shah, the CDC’s principal deputy director, said in a statement.
The agency said in an email to The Washington Post that it was able to get these additional shots quickly to providers because it “conveyed to the manufacturers the demand and the urgent need for additional doses … [and] were able to identify a batch that was awaiting final clearance and then worked with FDA to expedite processing.”
RSV is a highly contagious respiratory disease that can send as many as 80,000 children younger than 5 to the hospital each year, according to the CDC.
Nirsevimab, sold under the brand name Beyfortus, is not a vaccine. Instead, the single-dose shot offers similar protection by delivering lab-made antibodies that block invading viruses from entering cells. Lab data from the manufacturers showed that nirsevimab decreased the risk of hospitalization due to RSV by about 80 percent in infants under a year old.
In August, a CDC advisory committee recommended the drug to any healthy infant younger than 8 months during their first RSV season, and children up to 2 years old if they are at risk of developing severe disease.
Because of low supply, though, the agency tightened its recommendations in October. The updated recommendations prioritize babies younger than six months or with underlying health conditions. American Indian and Alaska Native babies should still be offered the preventive shots if they are younger than 8 months, the CDC said.
Some physicians say the troubles with the RSV treatment might be related to the lackluster interest in the coronavirus vaccine; many physicians assumed there would be little interest in an RSV shot, so providers opted not to order as many doses.
“A lot of private practices were really scared that they were going to buy a bunch of these doses when you did have to buy them upfront, [which] was happening with the coronavirus vaccine,” said Anita Patel, a pediatric critical care attending at Children’s National Hospital in Washington.
Cost has been a significant barrier to physicians preordering the doses. The Vaccines for Children program pays $395 per dose for the 100 milligram shot, and the private-sector cost is $495 per dose.
“I think it’s a little bit of gun shyness on the part of physicians who … did not want to [cover] … these vaccines that are high in costs,” Patel said.
The additional doses are likely not enough to fully address the shortage, according to experts, but many are hopeful that they will have a positive impact on communities who are disproportionally affected by RSV.
“I think this certainly will make a difference, and hopefully the distribution through VFC will make for more equitable availability,” said Playforth. “Hopefully increasing supply will mean that more babies who meet the original criteria will have access to the treatment.”
Outbreaks of RSV typically occur during late fall through early spring, with a peak in winter. This year, cases have already started rising in some Southern states, but experts say that rise is typical.
“We’re seeing RSV go up, but we don’t expect it to be a season like last year,” said Sean T. O’Leary, a pediatric infectious-diseases specialist at the University of Colorado and the chair of the committee on infectious diseases at the American Academy of Pediatrics. “We’re expecting more of a typical season, which is always bad but not quite to the unprecedented nature … that we saw last year.”