Respiratory syncytial virus (RSV)

Last content update: 2/27/25

Masks are required for patients, visitors, and staff in patient care areas of health care delivery facilities in Santa Clara County from November 1 through March 31.

The County’s Health Order Requiring Use of Face Masks in Patient Care Areas of Health Care Delivery Facilities During Designated Winter Respiratory Virus Period requires use of face masks in patient care areas of healthcare facilities from November 1 through March 31 of each year.

For more information, visit our Public Health Orders webpage.

Talk to your patients about getting immunized for RSV

Respiratory syncytial virus (RSV) is the most common cause of hospitalization in infants. It causes annual outbreaks of respiratory illnesses in all age groups. RSV vaccines are available to protect infants, toddlers, and older adults. A healthcare provider’s recommendation is one of the most important factors influencing a patient’s choice to accept a new preventive product or vaccine. It is important to help your patients get immunized and stay protected during the fall and winter seasons.

RSV maternal vaccine for pregnant people

Prenatal care providers should help protect newborns by ensuring that ABRYSVO RSV vaccine is administered this season to all pregnant patients at weeks 32 through 36 of pregnancy during September through January.

Timing of vaccination

ABRYSVO should be administered to pregnant persons who are 32–36 weeks pregnant during September to January to target vaccine to those whose infants will be in their first months of life during the RSV season.

Efficacy

Maternal vaccination protects against severe RSV illness during infant’s first 6 months, the period of highest risk for severe RSV disease. Data from clinical trials show that the estimated benefits of the recommended maternal RSV vaccine outweigh any potential risks.

For more information, visit the CDC’s RSV Vaccine Guidance for Pregnant People webpage.

Co-administration

It is acceptable to co-administer ABRYSVO to pregnant persons with other recommended vaccines (Tdap, flu, and COVID vaccines) without regard to timing, including simultaneous vaccination at different anatomic sites on the same day.

Contraindications

RSVpreF (ABRYSVO, Pfizer) should not be administered to a person with a history of severe allergic reaction, such as anaphylaxis, to any component of this vaccine. Information about ABRYSVO can be found in the manufacturer’s package insert.

Insurance coverage for the RSV vaccine

RSV vaccines should be covered by most private insurance and Medi-Cal.

RSV immunizations for infants and toddlers

Healthcare providers should provide information on both maternal vaccines and infant monoclonal antibody products and consider patient preferences when determining whether to vaccinate the pregnant patient or administer nirsevimab to the infant after birth.

Timing of immunization

Nirsevimab (Beyfortus) is recommended for:

Infants under 8 months old born during their first RSV if their birth parent did not receive an RSV vaccine.
Some children between the ages of 8 and 19 months who are at increased risk of severe RSV disease before their second RSV season.
- Children who have chronic lung
- Children with severe immunocompromise
- Children with cystic fibrosis who have severe disease
- American Indian and Alaska Native children

Efficacy

Maternal vaccination protects against severe RSV illness during infant’s first 6 months, the period of highest risk for severe RSV disease. Early real-world data show that nirsevimab was at least 80–90% effective in preventing babies from being hospitalized with RSV.

For more information, visit the CDC’s RSV Immunization Guidance for Infants and Young Children webpage.

Contraindications and precautions

Nirsevimab is contraindicated in infants and children with a history of severe allergic reactions (e.g., anaphylaxis) to nirsevimab or to any of its components. See nirsevimab FDA package insert.

It should be given with caution to infants and children with bleeding disorders. See General Best Practice Guidelines for Immunization for details on vaccinating persons with increased risk for bleeding.

Insurance coverage for RSV immunization (nirsevimab)

RSV immunizations for children should be covered by most private insurance plans. If the child is uninsured, underinsured, Medi-Cal eligible or American Indian/Alaskan Native, they are eligible to receive RSV and other recommended immunizations through the Vaccines for Children (VFC) program.

RSV vaccine for older adults

Adults 60 and older are recommended to receive one dose of either of the two recently approved RSV vaccines, ABRYSVO or AREXVY based on a shared clinical decision-making discussion.

Risk for severe RSV disease

Adults at highest risk for severe RSV include:

Adults with chronic heart or lung disease, such as asthma
Adults with weakened immune systems (e.g., HIV, or having cancer treatments)
Adults with certain other underlying medical conditions (e.g., diabetes, cancer, kidney disease, sickle cell disease)
Adults living in nursing homes or long-term care facilities

Timing of vaccination

RSV vaccines are approved for use as a single dose; there is no current indication for re-vaccination. Ideally, RSV vaccine should be administered before the onset of the RSV season. Currently, RSV vaccine should be offered to adults aged 60 years and up using shared clinical decision-making as early as the vaccine supply is available and should continue to offer vaccination to eligible adults who remain unvaccinated.

Efficacy

For information about the effectiveness of GSK’s AREXVY and Pfizer’s ABRYSVO RSV vaccines for older adults, visit the CDC’s RSV Vaccine Guidance for Older Adults webpage.

Co-administration

It is acceptable to co-administer either RSV vaccine with other adult vaccines without regard to timing, including simultaneous vaccination at different anatomic sites on the same day.

Contraindications and precautions

RSVPreF3 (AREXVY, GSK) should not be administered to a person with a history of severe allergic rection, such as anaphylaxis, to any component of this vaccine. Information about AREXVY can be found in the manufacturer’s package insert.

Insurance coverage for the RSV vaccine

RSV vaccines for adults should be covered by most private insurance, Medicare, and Medi-Cal.

Storage and handling practices for RSV vaccine and nirsevimab

Guidance for management of RSV and other respiratory viruses

Refer to the Respiratory virus guidelines webpage for isolation recommendations for RSV and other respiratory viruses for different settings, providers, and populations.

RESPIRATORY VIRUS GUIDELINES

RSV data for Santa Clara County

The County of Santa Clara Public Health Department monitors RSV activity during the respiratory virus season, which typically occurs October through the following May.

View the respiratory virus data dashboard