Patients aged 75 years or older who are not immunocompromised should receive a protein subunit respiratory syncytial virus (RSV) vaccine, according to new recommendations from the American College of Physicians. 

Two subunit vaccines are available in the US: Arexvy (GSK) or Abryvso (Pfizer). 

Adults aged 60-74 years who are considered high risk, such as those with chronic kidney, liver, or lung disease, should consider receiving a protein subunit vaccine. 

“A lot of Americans, especially older Americans, live with medical conditions that put them in the high-risk category, or they live with people with those conditions,” said Ana Weil, MD, MPH, assistant professor in the Division of Allergy and Infectious Diseases in the Department of Medicine at University of Washington in Seattle, who was not involved with the guidelines.

Other risk factors for the younger age group that would prompt a recommendation for the vaccine include having sickle cell disease, diabetes and obesity, or living in a long-term care facility. 

Because the risk for RSV-related hospitalization is lower among adults aged 60-74 years who do not have these conditions — and given the limited potential for developing Guillain-Barré syndrome — ACP limited routine vaccination to adults aged 75 years or older. 

RSV is associated with up to 160,000 hospitalizations and 10,000 deaths in adults over age 65 each year in the US. 

The recommendations are based on a systematic review of eight trials in adults aged 18 years or older who were not pregnant or immunocompromised. The review included one trial on the mRNA vaccine, with insufficient evidence for efficacy. 

The results showed protein subunit vaccines prevented an estimated 23 hospitalizations and 128 cases of severe illness per 100,000 adults older than 60 after one RSV season compared to those who received placebo or no vaccination. Protection against severe illness persisted into a second season, with 179 prevented cases per 100,000 people. The vaccine did not reduce all-cause mortality, and evidence beyond two seasons was limited. 

The RSV is only administered once, said Amir Qaseem, MD, chief science officer and senior vice president of the American College of Physicians, who authored the guidelines. 

“We need to see more from ongoing studies to understand if additional vaccination is needed, and if so, how long after,” Qaseem said. 

The vaccine did not increase overall serious adverse events, such as those leading to hospitalization, permanent disability, or death. However, it was associated with a small increase in risk for developing Guillain-Barré Syndrome. 

In the lower age bracket, shared decision-making should involve both a patient’s risk profile and that of their household. Clinicians should ask patients if they take care of grandchildren because young children are common vectors of transmission. 

“Those types of details are critical,” Weil said. “We know from household community studies that RSV is most likely to enter the household through a child, who then passes it on to other adults and infants.” 

No specific treatment exists for RSV, critical information that clinicians should relay to patients, Weil said. 

The research was funded by ACP. The sources cited in this article reported no disclosures.

Brittany Vargas is a journalist covering medicine, mental health, and wellness.