When a new respiratory syncytial virus vaccine for pregnant women was introduced last fall, Sarah Turner, a family physician at Lutheran Hospital in Indiana, couldn’t help but expect some backlash. She told me that at most, about half of eligible pregnant patients choose to get the flu vaccine, and “very few” would agree to get the COVID-19 vaccine. .
But to Turner’s surprise, patients were clamoring for the RSV vaccination, some even more enthusiastic than Tdap, which protects newborns from whooping cough and had previously been the easiest sell. This time, expectant parents started a conversation about vaccinations.
An estimated 58,000 to 80,000 children under the age of 5 are hospitalized each year in the United States due to respiratory syncytial virus.The risk is best for infantsSally Palmer, an immunologist and chief of pediatrics at NewYork-Presbyterian/Weill Cornell Medical Center, says the virus is their “number one enemy.” But this past season was the first time the U.S. was equipped with his two tools that could significantly reduce that damage. vaccines for pregnant peopleand then the antibodies can be passed on to the child. monoclonal antibodyKnown as nilsevimab, it is given directly to infants. Their arrival is “similar to the end of polio,” Anne-Marie Rick, a pediatrician and clinical researcher at Children’s Hospital of Pittsburgh, told me: Because both vaccinations are widely used, the youngest Winter disease risks may forever look different for people in the United States.
But some experts worry that these powerful shots are being wasted. The CDC’s seasonal recommendations governing their use may simply be “too strict,” Perma told me. Following these guidelines, many clinics stopped vaccinating mothers at the end of January. The main window for administering monoclonal antibodies is expected to close this weekend.The next eligibility period will not open for Month. The United States has two new vaccinations that protect very well against deadly respiratory viruses, and that people actually want to get, but are being held back from doing so.
There is logic to the guiding principles behind the CDC’s recommendations. RSV is seasonal virus, both injections are thought to provide protection for about 6 months. For maternal vaccines administered between 32 weeks of pregnancy and her 36 weeks, the baby’s clock of protection begins after birth. So if a pregnant person receives the vaccine in June, outside of the CDC’s recommended window, and gives birth in July, her child could become vulnerable again in February, usually before the RSV outbreak ends. There is sex. In theory, starting nilsevimab in her October, when RSV usually arrives, could better protect the infant in the spring and summer. Current guidelines also require her to choose between two options: Most infants who benefit from maternal vaccination are: Not eligible He will also receive nilsevimab.
However, this past season, nisevimab serious supply shortageWilliam J. Muller, a pediatric infectious disease expert at Northwestern University who helped conduct the monoclonal antibody trials, said the main reason is that drug companies underestimated demand. Additionally, many hospital systems balked at the cost of new drugs, which are more expensive than maternal vaccines and have not yet been factored in or included in the cost of delivering a newborn. consistently covered by insurance. The shortage has become so severe that Sanofi, the maker of nilsevimab, has already stopped accepting new orders for certain doses of the monoclonal antibody. October. CDC is health warning, is asking health care providers to limit these doses to only infants at highest risk. “In our hospital system, we had some for babies in the NICU, but that was literally all we had,” Lutheran Hospital’s Turner told me.
Nilsevimab should become more available this year. Spokespeople for AstraZeneca and Sanofi said the companies are “confident of meeting global demand” for antibodies in 2024. But last year set the bar pretty low. Then, when the dosing window opens in October (which may already have coincided with the RSV outbreak), parents who have not been able to vaccinate themselves or their babies will rush to get the vaccine. Supply could move quickly as people scramble to get more supplies, said Grace Lee, a pediatrician at Stanford University. he advised me on RSV guidance. (The CDC did not respond to a request for comment.) Opening the dosing window early for either vaccines or monoclonal antibodies could ease that burden: U.S. begins immunizing against influenza well before the start of the seasonLee said this is because “it is not realistic to vaccinate the entire U.S. population in one week.”
“RSV has been rampant” in recent years, thanks in part to pandemic mitigation measures, Perma told me. The virus was virtually non-existent in 2020, only to flare up again during a strangely early season that began during 2020. Summer 2021 In the past two seasons, the virus arrived a little earlier, starting with an increase in September. If this pattern holds true, waiting until September to vaccinate pregnant women or until October to vaccinate infants will leave many newborns vulnerable for weeks or months longer than necessary. may be placed.
Many experts predict that the RSV pattern will return to normal soon.For decades, the Consistency “This was remarkable,” said Drexel University pediatrician Sarah Long, who advised the CDC on both new RSV intervention guidelines. However, even in more predictable years, RSV transmission varies by region. It begins in the summer in the south and can last until spring in the north. Shabir Madhi, a vaccinologist at South Africa’s University of the Witwatersrand, said the recommendation was “not one-size-fits-all” across the United States. clinical trial About the mother’s vaccine.These are judgment calls: France opens window for nilsevimab Before than the US.Belgium allows some pregnant women to get vaccinated As early as spring.Britain is weigh Whether we offer both injections at any time of the year.
Karen Acker, a pediatrician at Weill Cornell University, said one argument for the current seasonal window is that if a vaccine or monoclonal antibody shot is given too early, recipients may no longer receive protection at the end of the season. He said that it is a matter of gender. However, Perma and his colleagues are hopeful that the effects of the new RSV intervention may last longer than five to six months, which is around the time of clinical trials. Stop directly We are testing their effectiveness. Early data on nisevimab, for example, suggests that a little bit of protection could trickle down into next season, Mueller told me.
RSV is also the greatest threat to children within the first few months of life, when their airways are still small and developing. Given the choice between vaccinating the mother a little earlier (which may leave older infants a little more vulnerable later in the season) or waiting to administer nirsevimab to younger infants; rear Now that RSV season has begun, the former may actually be a safer strategy. In addition, summer babies who are not given nisevimab in the hospital are less likely to become infected later, especially if their parents do not regularly take them to see their pediatrician. Joshua Salomon, a health policy researcher at Stanford University, said trying early is better than not trying at all.
In theory, the CDC guidelines do Allow room for adjustments in the management window depending on regional RSV trends. However, these decisions can be difficult to implement if providers must order in advance and store vials in limited space. So far, many clinics and hospitals are adhering to the number of months set out in CDC guidance. “The deadline is very arbitrary,” Rick told me. Early last season, infants 8 months and younger were denied nirsevimab after taking just one day over the recommended dose, Turner said. Many health care providers then stopped offering the maternal vaccine after January 31 or simply ran out of stock.
If the need and enthusiasm for vaccines and treatments is strong, it makes sense to take every opportunity to prevent them. Several experts I spoke to supported a wider window. Perma thinks the U.S. should even consider offering maternal vaccines year-round. In her view, restrictions on both seasonality and gestational age limit too strongly the chances of a baby being protected. Some health care providers also noted that given all the uncertainties, they recommend the maternal vaccine as the primary protection, leaving nirsevimab as a backup. Simply because the vaccine can be administered first.. Maternal vaccination can protect the baby from the moment of birth and is a kind of insurance that prevents problems with supply and delivery of nirsevimab. Expanding vaccination eligibility may not be a perfect solution. But by maximizing the immunizations that people actually want to receive, more infants could be protected when they are needed most.
