The Centers for Disease Control and Prevention has recommended rationing an important monoclonal antibody product to protect young infants from RSV due to strained supply of the new product, Sanofi’s Beyfortus.
In a health alert issued Monday, the CDC said clinicians should prioritize available doses for babies at highest risk from respiratory syncytial virus, reserving 100-milligram doses for infants under the age of 6 months and those with underlying health conditions that put them at higher risk of experiencing severe illness if they contract RSV.
The CDC alert comes as reports suggest RSV activity in the southern part of the country has reached seasonal epidemic levels, an indication that transmission elsewhere will likely climb in the coming month or two.
Products to protect babies from RSV — the No. 1 cause of hospitalization of infants in this country — have been long awaited. But the summer approval of Beyfortus created a relatively compressed timeline to make the product available for this fall. In addition, the high price tag — it costs $495 per dose — and uncertainty about how quickly and to what degree insurance companies would reimburse for it has led to a scramble among pediatric practices and birthing hospitals. A number have made the substantial changes needed to bring it on board for this fall while others have said they are likely to be unable to offer it for the 2023-24 season.
The CDC’s statement said availability of the monoclonal product, whose scientific name is nirsevimab, is also playing into the current shortage.
“Based on manufacturing capacity and currently available stock, there are not sufficient 100-mg dose prefilled syringes of nirsevimab to protect all eligible infants weighing [11 pounds or more] during the current RSV season,” the CDC said. “Additionally, supply of the 50-mg dose prefilled syringes may be limited during the current RSV season. CDC continues to work with the manufacturer to understand how it may accelerate nirsevimab supply.”
Sanofi had previously insisted it would have enough product to meet demand for Beyfortus and has even offered providers who purchase directly from the company the opportunity to delay payment for purchases until close to the end of the RSV season.
But in a statement Tuesday, the company acknowledged that “unprecedented” demand for the product had outstripped initial supplies.
“Despite an aggressive supply plan built to outperform past pediatric immunization launches, demand for this product, especially for the 100-mg doses used primarily for babies born before the RSV season, has been higher than anticipated,” a Sanofi spokesperson said via email.
The company said it is collaborating closely with the CDC to ensure that the Vaccines for Children program — a CDC-administered program that provides vaccines at no cost to children from low- or no-insurance households — get equitable access to available doses. And it said it is working with AstraZeneca, which makes Beyfortus, to accelerate additional supply and explore options for extending the manufacturing network. AstraZeneca developed nirsevimab, but licensed U.S. sales to Sanofi.
Rachel Fusfeld, a young mother of two children under the age of 3, has been asking since her second son’s birth in early August when she will be able to get him Beyfortus. She is still asking.
“We went for my son’s two-month pediatrician appointment last Monday and they said they hope to get them this month but didn’t have a concrete update nor firm timing to share,” Fusfeld said in an email Tuesday. She even contacted Sanofi, asking the company where in her area she might be able to find an available dose; she was told Sanofi did not have that information.
The CDC said children ages 8 months to 19 months with health conditions that would normally qualify them for Beyfortus should not receive the product this season. Instead, they should be offered a previously approved monoclonal antibody, Synagis (palivizumab), for the 2023-24 RSV season, the CDC added. Synagis was developed by AstraZeneca, which sold U.S. commercial rights to the product in 2018 to Swedish Orphan Biovitrum AB, known as Sobi.
The agency said, however, that American Indian and Alaska Native children ages 8-19 months should receive Beyfortus if they are not eligible for Synagis and live in remote regions, where transporting them to advanced medical care, should they need it, is more challenging or if they live in communities with known high rates of RSV among older infants and toddlers. Alaska Native children have among the highest rates of severe RSV in the world.
The CDC also recommended obstetricians, gynecologists, and others involved in prenatal care discuss with patients who are currently pregnant another option for protecting newborns — Pfizer’s vaccine for pregnant people, Abrysvo, which when given late in pregnancy induces antibodies that transfer across the placenta to protect a baby in their first 6 months of life.
The maternal RSV vaccine was recommended by CDC’s vaccine expert panel, the Advisory Committee on Immunization Practices, in late September. The vaccine, which must be given between weeks 32 and 36 of gestation, is recommended for pregnant people whose babies will be born between October and March, when RSV transmission is typically highest.
The CDC’s alert also warned health care providers against giving babies who would normally require 100 milligrams of Beyfortus two 50-milligram doses instead, to preserve the number of 50-milligram doses available for infants who need them, those weighing under 11 pounds. The agency noted health insurers may not cover two 50-milligram doses if given to a single child.
RSV is so ubiquitous among young children that most will have been infected for the first time by the age of 2. The virus infects at all ages but in older children, teens, and most adults, it manifests as a cold, albeit sometimes a nasty one. It can cause severe illness in older adults, for whom there are now two vaccines, Pfizer Abrysvo and GSK’s Arexvy.
But RSV does its worst damage in little kids, especially those in the first months of life when airways are not fully developed. Globally it is the second most common killer of children under the age of 1.
In the U.S., RSV deaths are not common — CDC estimates that between 100 and 300 children a year die from RSV infection — but the care needed to keep deaths down swamps pediatric hospitals across the country. It is estimated that between 58,000 and 80,000 children a year in this country are admitted to hospital for RSV care.