Developments in RSV Biologics
Respiratory syncytial virus, or RSV, is a negative-sense, single-stranded RNA virus. It is a common respiratory virus that usually causes mild, cold-like symptoms. In most regions of the United States, RSV season starts in the fall and peaks in the winter.
Although most people who develop RSV infection have mild illness, certain individuals are at risk for severe disease and death. It is estimated that between 60,000 and 160,000 older adults are hospitalized due to RSV, and between 6,000 and 10,000 older adults die due to RSV each year.
Among children younger than 5 years, 58,000 to 80,000 are hospitalized each year due to RSV; and 100 to 300 die from it.
Those at high risk for severe illness from RSV include:
- Premature infants
- Infants, especially those 6 months and younger
- Children younger than 2 years old with chronic lung disease or congenital heart disease
- Children with suppressed immune systems
- Children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions
- Older adults, especially those 65 years and older
- Adults with chronic lung or heart disease
- Adults with weakened immune systems
In 2004, the U.S. Food and Drug Administration (FDA) approved Synagis (manufactured by Sobi) the first monoclonal antibody used to prevent severe disease caused by RSV in high-risk infants. It must be given monthly throughout the RSV season.
In May 2023, FDA voted in support of approval for RSVpreF, Pfizer’s vaccine candidate to prevent severe disease caused by RSV in infants through vaccination of pregnant people. RSVpreF is currently under FDA review for the prevention of medically attended lower respiratory tract disease (MA-LRTD) and severe MA-LRTD caused by RSV. The FDA’s decision on the potential approval of RSVpreF is expected in August 2023.
Also in May, the FDA approved two RSV vaccines, Arexvy and Abrysvo, manufactured by GSK and Pfizer, respectively. FDA approved both vaccines for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older.
In June 2023, the ACIP voted to recommend Pfizer and GSK’s adult RSV vaccines for adults 60 and
In July 2023, FDA approved nirsevimab (AstraZeneca and Sanofi), a monoclonal antibody that will be used to protect newborns and infants born during or entering their first RSV season. In contrast to Synagis, it will only have to be given once in a season. Nirsevimab is the first passive immunization product to be considered for inclusion by the ACIP in the CDC immunization schedule as a vaccine-like seasonal immunization. The ACIP will meet to discuss recommendations for implementation and inclusion in the VFC program on August 3.
Vaccine/Antibody Availability and Insurance Coverage
RSV vaccines for older adults are expected to be available this fall.
These vaccines will be covered by Medicare Part D, Medicaid, and Affordable Care Act-compliant insurance plans. It is not yet known whether Arexvy and Abryvo will be included in the Vaccines for Adults at Risk (VFAAR) program.
CDC is assessing whether nirsevimab will be included in the Vaccines for Children (VFC) program, so its cost and availability is unknown at this time.
Developments in RSV vaccines are ongoing. Updates to vaccine product availability and insurance coverage of available vaccines are expected in the coming months.