Statement on the prevention of respiratory syncytial virus disease in older adults

What

Respiratory syncytial virus (RSV) is a common respiratory virus, and infants and older adults are at higher risk due to RSV. RSV can cause serious respiratory disease in older adults, particularly those at increased risk due to chronic medical conditions. RSV has a seasonal pattern of activity where infections are usually more common in the winter with variation in the timing and magnitude of the peak.

This statement focuses on the protection of adults at risk for severe RSV disease (including death and admission to hospital or intensive care units [ICU] due to age, medical conditions, setting and other potential factors. Health Canada has recently authorized two vaccines, both based on the prefusion stabilized F protein (preF), to protect adults from RSV:

• RSVPreF3 (Arexvy, GSK) is an AS01E adjuvanted vaccine authorized with an indication for all adults 60 years of age and over.
• RSVpreF (AbrysvoTM, Pfizer) is an unadjuvanted vaccine authorized with an indication for all adults 60 years of age and over. This formulation is also authorized for pregnant women and pregnant people who are at 32 to 36 weeks of gestation to protect infants from RSV.

Who

NACI recommends RSV immunization programs for adults 75 years of age and older, particularly for older adults with chronic health conditions who are at increased risk of severe RSV disease. NACI also recommends RSV immunization programs for adults 60 years of age and older who are residents of nursing homes and other chronic care facilities. Severe RSV disease in adults is most common in advanced age and in those with certain chronic health conditions or other risk factors. Adults with chronic health conditions who are at increased medical risk for severe RSV disease are highlighted in List 1. In addition, adults may be at increased risk of severe RSV disease due to factors that intersect with social determinants of health.

For individuals who may seek vaccination outside of a public health program, NACI recommends that RSV vaccines may be considered as an individual decision by adults 60 to 74 years of age in consultation with their health care provider. It is unknown at this time if these vaccines can be boosted by subsequent doses, and therefore healthy individuals who are less than 75 years of age may want to discuss deferring vaccination with their health care providers to a future time when they may be at greater risk. If an individual over the age of 75 is not included in a publicly funded program, NACI recommends vaccination for these individuals, particularly for those adults at increased risk of severe RSV disease.

The RSV vaccine is optimally administered just before the start of the RSV season. Jurisdictions are encouraged to define the RSV season and administer RSV vaccines based on local epidemiology (prior to the COVID-19 pandemic, the RSV season was typically November to April).

How

RSVPreF3 is administered intramuscularly using single dose vials of lyophilized powder which is reconstituted at the time of use with the accompanying vial of AS01E adjuvant suspension. A single 0.5mL dose of RSVPreF3 is authorized for administration in adults 60 years of age and older.

RSVpreF is administered intramuscularly using single dose vials of lyophilized powder which is reconstituted with sterile water (diluent) in a prefilled syringe. A single 0.5mL dose of RSVpreF is authorized for administration in adults 60 years of age and older.

Given the needs of older adults to be protected from multiple vaccine preventable diseases, some of which are seasonal, concurrent administration of an RSV vaccine with other adult vaccines is acceptable and supported. However, according to findings from coadministration studies of RSV vaccines with influenza vaccines, common side effects, such as fever and soreness at the injection site, may be increased when these two vaccines are administered on the same day. Some studies also suggest it is possible that the RSV and influenza vaccines may not produce as strong of an immune response if they are given on the same day, but the clinical significance of this is unknown. Additional research is ongoing to further inform guidance on same-day administration of the RSV vaccine and other adult vaccines, including the COVID-19 vaccine. If possible, RSV vaccine should be given at least 6 weeks before or after non-seasonal vaccines, for example, shingles or diphtheria-tetanus vaccines, to avoid inadvertently attributing an adverse event from another vaccine to the RSV vaccine.

For additional information, including supporting evidence and rationale for these recommendations, please see Recommendations.