RSV Vaccines for Adults 60 and Older: ACIP's 2023 Recommendation

This page describes the Advisory Committee on Immunization Practices' recommendation as issued in June 2023. Recommendations can change as new evidence emerges; check current CDC guidance.

Respiratory syncytial virus (RSV) causes seasonal epidemics of respiratory illness. The COVID-19 pandemic disrupted its usual timing, though the 2022–23 fall and winter epidemic suggested a gradual return to the prepandemic pattern. Each season RSV causes substantial illness and death in older adults, including lower respiratory tract disease (LRTD), hospitalization and death. Estimates vary widely because adults are undertested and standard tests may miss infections, but among adults 65 and older RSV is estimated to cause 60,000 to 160,000 hospitalizations and 6,000 to 10,000 deaths a year.

Who is at higher risk

• adults with chronic obstructive pulmonary disease, asthma, congestive heart failure, coronary artery disease, cerebrovascular disease, diabetes or chronic kidney disease;
• residents of long-term care facilities;
• people who are frail or of advanced age (hospitalization rates rise with age and are highest at 75 and older);
• people with weakened immune systems, including stem cell transplant recipients and those on immunosuppressive drugs for organ transplants, cancer or other conditions.

The vaccines

In May 2023 the Food and Drug Administration (FDA) approved the first vaccines to prevent RSV-associated LRTD in adults 60 and older, each given as a single 0.5 mL dose:

• RSVPreF3 (Arexvy, GSK), an adjuvanted (AS01E) recombinant stabilized prefusion F protein vaccine;
• RSVpreF (Abrysvo, Pfizer), a recombinant stabilized prefusion F protein vaccine.

ACIP's RSV adult work group met at least monthly from May 2022, reviewing one phase 3 and one phase 1/2 randomized trial for each vaccine and grading the certainty of evidence with the GRADE approach. It counted Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy and acute central nervous system inflammation within 42 days of vaccination as inflammatory neurologic events.

Efficacy

Neither trial was large enough to estimate protection against hospitalization, severe illness needing breathing support, or death; there were very few such events (for hospitalization, one in the vaccine group and five in the placebo group for GSK, one versus three for Pfizer) and no deaths.

Safety

• Severe short-term reactions (grade 3 local or body-wide reactions within days): 3.8% of GSK vaccine recipients versus 0.9% with placebo; 1.0% of Pfizer vaccine recipients versus 0.7% with placebo.
• Serious adverse events were about equally common with vaccine and placebo in both trials (GSK 4.4% versus 4.3%; Pfizer 4.3% versus 4.1%).
• Atrial fibrillation within 30 days was reported by more vaccine recipients than placebo recipients in both trials (10 versus four in each), though numbers were small; in the Pfizer trial, six of the 10 vaccine recipients had a history of the condition.
• Inflammatory neurologic events occurred in three of 17,922 GSK vaccine recipients and three of 20,255 Pfizer vaccine recipients across all trials in older adults. For GSK: one case of GBS in a 78-year-old in Japan, and two reports of acute disseminated encephalomyelitis (ADEM) in 71-year-olds at the same site in South Africa after receiving the RSV and influenza vaccines together, both diagnosed without confirmatory testing; in the fatal case the investigator later revised the diagnosis to hypoglycemia and dementia. For Pfizer: GBS in a 66-year-old in the United States, Miller Fisher syndrome (a GBS variant) in a 66-year-old in Japan, and a polyneuropathy worsening in a 68-year-old in Argentina. Whether these were chance events or caused by vaccination was unknown.

The recommendation

On June 21, 2023, ACIP recommended that adults aged 60 and older may receive a single dose of RSV vaccine, using shared clinical decision-making.

Both vaccines showed moderate to high efficacy against RSV LRTD over two seasons, which suggests they could prevent considerable illness. But because of the possible neurologic signal, ACIP advised targeting vaccination, until more safety data are in, to those at highest risk of severe RSV and most likely to benefit. Shared clinical decision-making leaves the decision to a conversation between clinician and patient, guided by the patient's risk, values and preferences, the clinician's judgment and the vaccine's characteristics.

The people most likely to benefit include those with lung disease such as COPD or asthma; heart disease such as heart failure or coronary artery disease; moderate or severe immune compromise; diabetes; neurologic or neuromuscular conditions; kidney, liver or blood disorders; frailty; advanced age; residence in a nursing home or other long-term care facility; and other conditions a clinician judges to raise the risk. Few frail, very old or long-term care residents were in the trials, and people with weakened immune systems were excluded, but they may still be vaccinated given the potential benefit.

Practical guidance

• Timing: one dose; there was not enough evidence to judge whether revaccination is needed. Ideally vaccinate before RSV season, but since the season had not returned to its usual pattern, clinicians were advised to offer the vaccine for the 2023–24 season as soon as supply was available and to keep offering it.
• Other vaccines: giving RSV vaccine at the same visit as other adult vaccines is acceptable, though data are limited. With influenza vaccines, immune responses were somewhat lower, and one influenza strain fell short of noninferiority with the GSK vaccine and adjuvanted flu vaccine; the clinical significance is unknown. There were no data on giving it with COVID-19, pneumococcal, Tdap or recombinant zoster vaccines (the last shares the GSK vaccine's adjuvant). Clinicians should weigh whether the patient is up to date, the chance of a return visit, disease risk, reactions and preferences, and separate injection sites by at least an inch where possible.
• Precautions: delay vaccination during moderate or severe acute illness. Do not give it to anyone with a history of severe allergic reaction, such as anaphylaxis, to any vaccine component.
• Reporting: report any clinically significant adverse event to the Vaccine Adverse Event Reporting System (VAERS) at vaers.hhs.gov or 1-800-822-7967, even if it is unclear whether the vaccine caused it.

What comes next

CDC will watch for GBS, ADEM and other neurologic events through VAERS and the Vaccine Safety Datalink and will prioritize measuring effectiveness against hospitalization. Under FDA requirements, GSK will study the risks of GBS, ADEM and atrial fibrillation, and Pfizer will study GBS and atrial fibrillation; both companies will study a second dose.

Sources

• Melgar M, Britton A, Roper LE, et al. Use of Respiratory Syncytial Virus Vaccines in Older Adults: Recommendations of the Advisory Committee on Immunization Practices — United States, 2023. MMWR Morb Mortal Wkly Rep 72(29). https://www.cdc.gov/mmwr/volumes/72/wr/mm7229a4.htm
• Vaccine Adverse Event Reporting System: https://vaers.hhs.gov/index.html