Use of the Pfizer Respiratory Syncytial Virus Vaccine During Pregnancy for the Prevention of Respiratory Syncytial Virus-Associated Lower Respiratory Tract Disease in Infants: Recommendations of the Advisory Committee on Immunization Practices - United States, 2023.

Before the introduction of universal respiratory syncytial virus (RSV) immunization recommendations for infants, RSV was the leading cause of hospitalization among infants in the United States. Since 2023, CDC's Advisory Committee on Immunization Practices (ACIP) has recommended that all infants be protected against RSV-associated lower respiratory tract infection (LRTI) through either 1) maternal RSV vaccination during pregnancy (Abrysvo, Pfizer) or 2) administration of nirsevimab (Beyfortus, Sanofi and AstraZeneca), a long-acting RSV monoclonal antibody, to the infant. In June 2025, the Food and Drug Administration licensed clesrovimab (Enflonsia, Merck), a second long-acting RSV monoclonal antibody, for prevention of RSV-associated LRTI in infants. Since September 2024, the ACIP Maternal/Pediatric RSV Work Group has reviewed evidence regarding the safety and efficacy of clesrovimab use in infants. On June 26, 2025, ACIP recommended clesrovimab as a second long-acting monoclonal antibody product that could be used as an alternative to nirsevimab for prevention of RSV-associated LRTI among infants aged <8 months who are born during or entering their first RSV season and who are not protected through maternal RSV vaccination. All infants should be protected against RSV-associated LRTI through use of one of these three products (i.e., maternal RSV vaccination or administration of nirsevimab or clesrovimab to the infant). No one product is preferred; the choice should be guided by parent preference, product availability, and timing of the infant's birth relative to the RSV season.

Respiratory syncytial virus (RSV) is the leading cause of hospitalization among U.S. infants. In July 2023, the Food and Drug Administration approved nirsevimab, a long-acting monoclonal antibody, for passive immunization to prevent RSV-associated lower respiratory tract infection among infants and young children. Since October 2021, the Advisory Committee on Immunization Practices (ACIP) Maternal and Pediatric RSV Work Group has reviewed evidence on the safety and efficacy of nirsevimab among infants and young children. On August 3, 2023, ACIP recommended nirsevimab for all infants aged <8 months who are born during or entering their first RSV season and for infants and children aged 8-19 months who are at increased risk for severe RSV disease and are entering their second RSV season. On the basis of pre-COVID-19 pandemic patterns, nirsevimab could be administered in most of the continental United States from October through the end of March. Nirsevimab can prevent severe RSV disease among infants and young children at increased risk for severe RSV disease.

BackgroundIn 2023, respiratory syncytial virus (RSV) vaccines were approved by the United States (US) Food and Drug Administration (FDA) for adults aged ≥60 years and recommended by the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) using shared clinical decision-making (SCDM). This study evaluated healthcare professional (HCP) characteristics associated with RSV vaccination knowledge and practices.MethodsA cross-sectional online survey targeting approximately 600 HCPs was conducted in November 2023 to assess HCP knowledge, attitudes, and practices related to older adult RSV vaccination. Three logistic regression models used these survey data to explore HCP characteristics associated with RSV vaccination knowledge and practices (e.g., likelihood of knowing FDA indication and ACIP recommendation). The models included HCP type as a covariate a priori, with other covariates determined using backwards selection with a prespecified stay criterion (P < 0.1).ResultsThe survey was completed by 603 HCPs (Table 1). HCPs had higher odds of being knowledgeable about the FDA indication and ACIP recommendation for older adult RSV vaccination if their workplace stocked RSV vaccine(s); odds were lower if HCPs were least familiar with RSV disease or had a higher percentage of non-White adult patients (Table 2). Odds of initiating RSV vaccination conversations with ≤5% of older adult patients were higher among HCPs who were less familiar with RSV disease, felt less confident in SCDM conversations, and perceived RSV protection to be less important than other respiratory infections (Table 3). Being less familiar with RSV disease was also associated with higher odds of not recommending/administering RSV vaccines to any older adults in the past 3 months (Table 4).ConclusionHCP familiarity with older adult RSV disease was associated with RSV vaccination knowledge and practices, highlighting the importance of continued RSV disease awareness efforts. Results can be used to tailor these efforts towards HCPs with potential vaccination knowledge and practice gaps to help ensure equitable RSV vaccination access across older adults.FUNDING: GSK (study identifier: VEO-000726)DisclosuresElizabeth M. La, PhD, GSK: employee|GSK: Stocks/Bonds (Private Company) David Singer, PharmD, MS, GSK: employee|GSK: Stocks/Bonds (Public Company) Eric Davenport, MStat, MEcon, GSK: study funding Andrea Harmelink, PhD, FNP, GSK: Stocks/Bonds (Public Company)

An Update on Childhood and Adolescent Vaccines

BackgroundSince June 2024, CDC’s Advisory Committee on Immunization Practices (ACIP) has recommended a single dose of RSV vaccination for all adults aged ≥75 years and for adults aged 60–74 years who are at increased risk of severe RSV disease. RSV vaccines are effective in preventing RSV-associated hospitalization, with the potential to prevent tens of thousands of annual hospitalizations and deaths in older adults. However, certain adults aged < 60 years are also at increased risk of severe illness caused by RSV.MethodsIn considering RSV vaccination for adults aged 50–59 years, ACIP reviewed risk of RSV-associated hospitalization among adults with and without chronic medical conditions, differential risk by race and ethnicity, duration of vaccine protection and potential need for revaccination, risk of Guillain-Barre syndrome (GBS) associated with subunit RSV vaccines, national vaccine uptake, societal costs of the vaccination program, complexity of changes to the immunization schedule, and challenges in implementing a risk-based recommendation in retail pharmacies, where most older adults have received RSV vaccination.ResultsACIP members discussed variability in individual-level risk of severe RSV disease in persons with specific chronic conditions and the balance of benefits and risks of RSV vaccination in adults aged < 60 years, who generally experience lower risk of severe outcomes from RSV infection compared with older adults. Members were concerned about the disproportionate burden of severe RSV disease and higher prevalence of chronic medical conditions among Black adults in the U.S., particularly in the 50–59-year age group. Members expressed a need for more data to inform optimal timing of revaccination after vaccine-induced immunity wanes, which is particularly important for younger adults with longer remaining life expectancy.ConclusionOverall, Committee members thought that the public health benefits of RSV vaccination outweighed risks for adults aged 50–59 years with certain chronic medical conditions. On April 16, 2025, ACIP recommended a single dose of RSV vaccine for these adults using the same qualifying risk conditions used for adults aged 60–74 years. ACIP plans to consider RSV vaccine recommendations for adults aged 18–49 years at a future public meeting.DisclosuresHelen Y. Chu, MD, MPH, Roche: Advisor/Consultant|Vir: Advisor/Consultant

Background During the 2024–2025 respiratory syncytial virus (RSV) season in the United States (US), RSV vaccination was recommended by the Advisory Committee on Immunization Practices (ACIP) for all adults aged ≥ 75 years and adults aged 60–74 years at increased risk for severe RSV disease. This study evaluated RSV-related knowledge, attitudes, and practices (KAP) among US healthcare professionals (HCPs), including primary care physicians (PCPs) and specialist physicians. Methods A cross-sectional online survey of RSV-related KAP was administered to US HCPs between December 2024–January 2025. The survey targeted 700 HCPs, including PCPs (n=200), specialists (n=150), nurse practitioners and physician assistants (n=150), and pharmacists (n=200). Descriptive results are presented here on PCPs’ and specialists’ knowledge of adult RSV disease and vaccination, RSV-related attitudes, RSV vaccination practices, and potential vaccination barriers. Results The final sample of 700 HCPs included 199 PCPs and 153 specialists (50 cardiologists, 50 endocrinologists, and 53 pulmonologists). Most PCP and specialist respondents reported being very familiar with RSV disease (83.9% and 80.4%, respectively). At the time of data collection, 81.3% of PCPs and 75.0% of specialists were aware that RSV vaccines were ACIP-recommended among all adults aged ≥ 75 years. However, fewer respondents were aware of the risk-based ACIP recommendation for adults aged 60–74 years (32.8% of PCPs and 27.0% of specialists). Most respondents perceived a benefit of having RSV vaccines available and recommended for all adults aged 60–74 years. Although more than 80% of PCPs and specialists reported recommending RSV vaccines to their eligible patients, these recommendations were not provided to all eligible patients consistently. Patient refusal or hesitancy was the most frequently reported barrier to recommending RSV vaccination to adults aged ≥ 60 years. Conclusion Despite the familiarity of RSV disease among PCPs and specialists, additional efforts may be needed to address potential knowledge and practice gaps. These findings can help to inform HCP and patient education to support RSV vaccination among eligible patients. Funding: GSK VEO-001082 Disclosures Elizabeth M. La, PhD, GSK: Employed by GSK|GSK: Stocks/Bonds (Public Company) Kyli Gallington, MPH, Evidera: Employed by Evidera|GSK: Employed by Evidera, which received funding from GSK to conduct this study David Singer, PharmD, MS, GSK: Employed by GSK|GSK: Stocks/Bonds (Public Company) Zaneta Balantac, ScB, Evidera: Employed by Evidera at the time of this study|GSK: Formerly employed by Evidera, which received funding from GSK to conduct this study Noha S. Eltoukhy, PharmD, MPH, GSK: Employed by GSK|GSK: Stocks/Bonds (Public Company) Yipin Han, MHS, Evidera: Employed by Evidera|GSK: Employed by Evidera, which received funding from GSK to conduct this study Donald M. Bushnell, MA, Evidera: Employed by Evidera|GSK: Employed by Evidera, which received funding from GSK to conduct this study

Universal hepatitis B vaccination in adults aged 19–59 years: Updated recommendations of the advisory committee on immunization practices—United States, 2022

Prevention and Control of Influenza With Vaccines: Recommendations of the Advisory Committee on Immunization Practices, United States, 2015–16 Influenza Season

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in neonates, infants, and children worldwide. The virus is estimated to infect 97% of this population in the United States by the age of 2 years, leading to hospitalization for severe lower respiratory tract disease in 2-3% of infants younger than age 6 months. Two preventive options, prenatal administration of a maternal vaccine and administration of a long-acting monoclonal antibody to the infant, are now available for the prevention of RSV-associated lower respiratory tract infection in infants in the United States. The U.S. Food and Drug Administration (FDA) has approved and the Centers for Disease Control and Prevention (CDC) has recommended a new maternal vaccination, RSVPreF, to be administered between 32 0/7 and 36 6/7 weeks of gestation to reduce the risk of RSV-associated lower respiratory tract infection in infants in the first 6 months of life. The monoclonal antibody nirsevimab was approved by the FDA and recommended by the CDC for prevention of RSV-associated lower respiratory tract infection in infants younger than age 8 months who are born during or entering their first RSV season and for infants and children aged 8-19 months who are at high risk for RSV-associated lower respiratory tract infection and entering their second RSV season. Either maternal vaccination during pregnancy or monoclonal antibody administration to the infant is recommended to prevent RSV-associated lower respiratory tract infection among infants, but both are not needed for most infants. Given that the availability of these products may vary as these recommendations are implemented, it is important that obstetricians and other prenatal practitioners have the information they need to counsel their pregnant patients about both options. We review the safety and efficacy of these products, current recommendations for their use, and relative advantages and disadvantages of both newly approved options for the prevention of RSV-associated lower respiratory tract infection in infants to assist obstetricians and other prenatal practitioners in their counseling of pregnant patients.

The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza and COVID-19 vaccination for all persons aged ≥6 months, including adults aged ≥18 years. ACIP also recommends a single lifetime dose of respiratory syncytial virus (RSV) vaccine for adults aged ≥75 years and for those aged 60-74 years who are at increased risk for severe RSV disease. Data from the National Immunization Survey-Adult COVID Module, a random-digit-dialed cellular telephone survey of U.S. adults aged ≥18 years, are used to monitor influenza, COVID-19, and RSV vaccination coverage. By the week ending November 9, 2024, an estimated 34.7% of adults aged ≥18 years reported having received an influenza vaccine, and 17.9% reported having received a COVID-19 vaccine for the 2024-25 respiratory virus season; 39.7% of adults aged ≥75 years, and 31.6% of adults aged 60-74 years at increased risk for severe RSV, had ever received an RSV vaccine. Coverage varied by jurisdiction and demographic characteristics and was lowest among younger adults and those without health insurance. Although early season estimates indicate that many adults are unprotected from respiratory virus infections, many appeared open to vaccination: overall, approximately 35% and 41% of adults aged ≥18 years reported that they definitely or probably will receive or were unsure about receiving influenza and COVID-19 vaccines, respectively, and 40% of adults aged ≥75 years reported that they definitely or probably will receive or were unsure about receiving RSV vaccine. Health care providers and immunization programs still have time to expand outreach activities and promote vaccination to increase coverage in preparation for the height of the respiratory virus season. Using these data can help health care providers and immunization programs identify undervaccinated populations and understand vaccination patterns to guide planning, implementation, and evaluation of vaccination activities.

Use of Respiratory Syncytial Virus Vaccines in Older Adults: Recommendations of the Advisory Committee on Immunization Practices — United States, 2023

Clinical Practice Guidelines and Recommendations: Room for Dissent?

Prevention and Control of Seasonal Influenza With Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP)—United States, 2014–15 Influenza Season

What Gastroenterologists Should Know About COVID-19 Vaccines

Respiratory syncytial virus (RSV) is a major cause of serious acute lower respiratory tract infection in infants and the elderly. The lack of a licensed RSV vaccine calls for the development of vaccines with other targets and vaccination strategies. Here, we construct a recombinant protein, designated P-KFD1, comprising RSV phosphoprotein (P) and the E.-coli-K12-strain-derived flagellin variant KFD1. Intranasal immunization with P-KFD1 inhibits RSV replication in the upper and lower respiratory tract and protects mice against lung disease without vaccine-enhanced disease (VED). The P-specific CD4+ Tcells provoked by P-KFD1 intranasal (i.n.) immunization either reside in or migrate to the respiratory tract and mediate protection against RSV infection. Single-cell RNA sequencing (scRNA-seq) and carboxyfluorescein succinimidyl ester (CFSE)-labeled cell transfer further characterize the Th1 and Th17 responses induced by P-KFD1. Finally, we find that anti-viral protection depends on either interferon-γ (IFN-γ) or interleukin-17A (IL-17A). Collectively, P-KFD1 is a promising safe and effective mucosal vaccine candidate for the prevention of RSV infection.