ACIP Expands Pfizer’s RSV Vaccine Recommendation to At-Risk Adults 50–59
Pfizer Inc. (NYSE: PFE) announced that the U.S. Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) has voted to expand its recommendation for the use of respiratory syncytial virus (RSV) vaccines in adults aged 50–59 who are at increased risk for RSV-associated lower respiratory tract disease (LRTD). This expanded recommendation includes ABRYSVO® (Respiratory Syncytial Virus Vaccine), which received FDA approval in October 2024 for adults 18–59 with heightened risk of severe RSV disease.
Each year, the CDC estimates that RSV causes between 15,000 and 20,000 hospitalizations among U.S. adults aged 50–59. Those at greatest risk include individuals with underlying health conditions such as obesity, cardiovascular disease, diabetes, chronic obstructive pulmonary disease (COPD), asthma, or other chronic or immunocompromising conditions.
Following the ACIP vote, the updated recommendation reads:
“ACIP recommends adults 50–59 years of age who are at increased risk of severe RSV disease receive a single dose of RSV vaccine.”
“With its vote to expand adult RSV vaccination recommendations, ACIP has taken an important step toward protecting individuals aged 50 to 59 who have underlying medical conditions that increase their risk for severe RSV illness,” said Dr. Alejandro Cane, Vice President and U.S. Medical Lead for Vaccines and Antivirals at Pfizer. “We are proud that ABRYSVO now holds the broadest indication among RSV vaccines, covering older adults, at-risk adults as young as 18, and pregnant women to help protect infants.”
The new guidance lowers the age threshold from 60 to 50 for high-risk adults. It is pending final approval by the CDC Director and the U.S. Department of Health and Human Services.
Understanding RSV and Its Risks
Respiratory syncytial virus (RSV) is a highly contagious virus that causes respiratory infections in people of all ages. It is a leading cause of serious respiratory illness, particularly in older adults, infants, and those with preexisting medical conditions. The virus can inflame the lungs and airways, potentially resulting in hospitalization or death in vulnerable individuals.
Certain chronic conditions—including cardiovascular and lung disease, diabetes with complications, moderate to severe immune compromise, and severe obesity—can significantly increase a person’s risk for severe RSV outcomes. RSV has two major subtypes, RSV-A and RSV-B, which may co-circulate or alternate in prevalence during seasonal outbreaks.
About ABRYSVO®: Broadest Indication Among RSV Vaccines
ABRYSVO is an unadjuvanted, bivalent RSV vaccine developed by Pfizer. It is designed to offer comprehensive protection against LRTD caused by RSV-A and RSV-B. The vaccine targets the RSV prefusion F protein, a critical structure for viral entry and the focus of neutralizing antibodies.
Pfizer is currently the only company with an RSV vaccine approved in the U.S. for:
- Adults aged 60 and older
- Adults 18–59 at increased risk of RSV-related LRTD
- Pregnant individuals (32–36 weeks gestation) to help protect infants from birth to six months
The vaccine has also received regulatory approval for both adult and maternal immunization across multiple countries, including the European Union.
Regulatory and Advisory Milestones
- May 2023: FDA approves ABRYSVO for adults aged 60 and older
- August 2023: FDA approves use in pregnant individuals for infant protection; ACIP supports maternal RSV vaccination during September–January
- October 2024: FDA approves ABRYSVO for adults 18–59 at increased risk
- March 2025: European Commission expands ABRYSVO’s indication to include broader adult populations
- April 2025: ACIP recommends RSV vaccination for high-risk adults aged 50–59
Important Safety Information
ABRYSVO should not be administered to individuals with a known severe allergic reaction to any component of the vaccine. Key safety considerations include:
- Guillain-Barré Syndrome (GBS): An increased risk was observed post-vaccination
- Pregnancy Timing: To avoid the potential risk of preterm birth, ABRYSVO should be administered only between 32–36 weeks gestation
- Fainting: May occur after any injectable vaccine—patients should be monitored to prevent injury
- Immunocompromised Individuals: May exhibit a reduced immune response
Common side effects (≥10%) include:
- Adults 60+: Fatigue, headache, injection site pain, muscle aches
- Adults 18–59: Injection site pain, muscle and joint pain, nausea
- Pregnant Individuals: Injection site pain, headache, muscle pain, nausea
Clinical trials also noted slightly higher rates of low birth weight and jaundice in infants whose mothers received ABRYSVO compared to placebo.
As RSV continues to pose a seasonal threat, especially to those with chronic conditions, expanded access to preventive tools like ABRYSVO represents a meaningful step in protecting vulnerable populations and reducing hospitalizations related to severe respiratory illness.
