Nirsevimab Administration During the Birth Hospitalization Free

This is a retrospective chart review of all newborns who were discharged from the newborn nursery and NICU between December 1, 2023, and March 31, 2024, from an urban academic medical center in the [Bronx]. The hospital only had access to VFC-supplied nirsevimab in late November 2023. There was limited commercial-payer nirsevimab available at this site. All newborns discharged from the newborn nursery and the NICU during the RSV season were included. Exclusion criteria included newborns whose birthing parents received the RSVpreF vaccine. Hepatitis B vaccine administration rate was used as a surrogate marker of newborn immunization acceptance in families. Birthing parent characteristics were studied along with the hepatitis B vaccine and nirsevimab immunization rates. Data extraction included the birthing parent’s age, parity, race, ethnicity, and mode of delivery. It also included the newborn’s gestational age, gender, and whether they were admitted to the NICU. This study was approved by the Albert Einstein College of Medicine, Montefiore Medical Center IRB. Data were stored on secure, password-protected computers and only accessible to the authors. Statistical descriptive analyses were performed for categorical variables and χ² and Fisher exact tests were used for proportions using GraphPad Prism.

There were 312 newborns discharged during this study period. After review, 288 (92.3%) were eligible for the VFC program. Of these, 51 newborns were excluded from this group for the following reasons: birthing parent received the RSVpreF vaccine (n = 32, 11.1%), nirsevimab was not discussed with the family (n = 16, 5.6%), nirsevimab was not available (n = 1, 0.3%), and the birthing parent vaccination record was unavailable (n = 2, 0.7%) (Fig 1). There were 237 newborns included in the data analysis. Hispanic families made up 53% of the group, the average age of birthing parents was 27.7 years, and this was the first child for 43.9% of birthing parents. Overall, 55.7% of newborns received nirsevimab. There were no differences in the administration rate of nirsevimab based on the birthing parent’s age, parity, ethnicity, or race (Table 1). There were no differences based on the need for a NICU or mode of delivery, 55%, cesarean section 54.4% and vaginal delivery 52.6%, respectively. Combining the prenatal RSVpreF vaccine birthing group and the nirsevimab-received newborns, 164 (61%) newborns were protected against RSV.

The administration rate of the hepatitis B vaccine birth dose was 97.1%. There were no differences in administration rate of the hepatitis B vaccine based on the birthing parent’s age, parity, ethnicity, or race. All newborns who received nirsevimab also received the hepatitis B vaccine; thus, there were no differences in characteristics of the birthing parents between the hepatitis B vaccinated and nirsevimab vaccinated groups (Table 2).

This is one of the earliest studies examining the administration rate of nirsevimab during the birth hospitalization and demonstrated that just over half of the families assented to the nirsevimab administration. Hepatitis B vaccine immunization was used as a surrogate in this population to highlight the general acceptance of newborn immunizations. This population is very receptive to newborn immunizations as appreciated by the high hepatitis B vaccine administration rate and recognition by the Immunization Action Coalition. However, families in this study were not as willing to receive nirsevimab.

There are several factors to consider when recommending and implementing a new immunization regimen targeted at newborns. The medical science supports nirsevimab, though education for families and medical staff was lacking. Many families reported the birth hospitalization was their first time hearing about RSV and this method of immunization. This is an obvious challenge for medical staff to educate new families on new monoclonal antibody immunizations. Moving forward, families should be educated early on in pregnancy. We plan to distribute RSV information and prevention to the prenatal clinics and the labor and delivery unit to increase the number of birthing parents who receive RSVpreF. Yarnall et al concluded that most new parents determine their vaccine plan before pregnancy.⁵  Additionally, to capture older infants and toddlers, it is important to also target the public. A successful immunization program was demonstrated in Spain that included immunization for all, easy access to appointments, including nontraditional work hours, and numerous locations.⁶  There were also supply chain issues that limited the opportunity to offer the immunization at the medical center. The demand seemed to be higher than the supply for the first season of nirsevimab.

RSV affects nearly all children by the age of 2 years,²  and many families with at least 1 child may already be aware of the illness and likely want protection for their future children. However, this was not the case in this study because there was no difference in the administration rates between newborns who had older siblings and this first pregnancy. Families are likely unaware of RSV and its potential sequelae. Unexpectedly, we noted that 5% of families were not informed of the opportunity to receive nirsevimab during the birth hospitalization. Increased education regarding the mediation's benefits for nursing staff and physicians is vital for a successful rollout. This RSV prophylaxis was only approved 3 months before the start of RSV season, which led to limited time for the hospital systems to ensure all workflows were in place.

One of the strengths of this study is its diverse population. Within the past few years, it was reported that only 60% to 70% of non-White and uninsured or Medicaid children followed the recommended vaccine schedule by 19 months of age,⁷  and the median hepatitis B rate in New York City was 87.4%.⁷  Our study group exceeded both metrics. Recently, the hospital implemented standing orders for all newborns that include the hepatitis B vaccine, and most newborns now get the vaccine within 12 hours of life as recommended by the New York Department of Health. In the future, we will try to include nirsevimab in the newborn’s routine orders to be administered during the season. This may increase earlier administration of nirsevimab.

This study captures nirsevimab administration data for its first RSV season. It has been more than 30 years since the introduction of a newborn birth hospitalization immunization. This allowed us to evaluate the baseline acceptance rate of a new immunization in the current state of patients’ heightened medical mistrust after a recent worldwide pandemic. The key to capturing nirsevimab immunization and its usefulness is limited to the first 2 years of life because the immunization is time-sensitive and not recommended after this age. This information will allow researchers to examine the RSV prophylaxis efficacy.

This study does have its limitations. First, it is retrospective and not feasible to understand all factors affecting those patients who did not receive nirsevimab. This study also did not span the entire RSV season because of the time required to operationalize the administration processes. The data here include 80% of the season and are a good representation of all newborns in our hospital. Additionally, more newborns may have been protected by receiving RSV prophylaxis in the outpatient setting. However, a majority of patients had follow-up care within the same medical center, where there was a very limited supply of nirsevimab in the outpatient setting. This is also a single-center trial, and reports may not be reproducible in other environments. Because of the VFC-limited supply of nirsevimab, non–VFC-eligible newborns were excluded. It is unknown if the commercial-payer population would have been equally receptive to this new immunization.

Unfortunately, there were a few barriers discovered during this study. In addition to the limited VFC-supply, medical teams were unaware of nirsevimab’s availability at the medical center. In these situations, newborns were excluded because the goal was to determine the administration rates without any obstacles. Additionally, this population may be unique in its extremely high rate of hepatitis B vaccination among newborns during birth hospitalization; therefore, the acceptance rate may be not reproducible at other medical centers. Finally, the level of education was not assessed in this study. Previous data indicate that college-educated persons are more likely to vaccinate their children.⁹ 

Future efforts to increase the protection of newborns and infants from RSV should include increased administration of the prenatal RSVpreF vaccine and nirsevimab. Strategies for success include educating obstetrical and newborn physicians, midwives, advanced practitioners, and nursing staff about the available birthing parent vaccine and pediatric immunization against RSV. Additionally, increasing parent and family knowledge on RSV and its risks as well as the safety and benefits of nirsevimab would be beneficial. Prenatal clinics offer a chance to start the conversation for newborn protection with families before delivery. Trust between the caregiver, patient, and family is essential when discussing prenatal vaccines and the administration of newborn nirsevimab. There are multiple points of contact with the birthing parents during pregnancy that allow time for better communication and understanding of RSV. The utilization of social media is another opportunity to increase awareness about prenatal and postnatal interventions, safety, and the benefits more broadly.

More than half of the newborns in this population were immunized during the birth hospitalization with the nirsevimab during the 2023–2024 season. Using a combination of both maternal vaccination and newborn immunization strategies, nearly two thirds of newborns at this institution will be protected from a serious RSV infection this year. This study also highlights an opportunity for a quality improvement initiative to increase the uptake of prenatal RSVpreF and newborn nirsevimab administration.