First-Ever RSV Vaccine for Adults 60 and Older Approved by FDA

The FDA has approved the first vaccine for respiratory syncytial virus (RSV), a disease causing lower respiratory tract illness and pneumonia that can be life-threatening. The vaccine is manufactured by GlaxoSmithKline Pharmaceuticals under the name Arexvy and is approved for use in individuals aged 60 and older, who are at high risk for severe disease caused by RSV. Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, called the vaccine approval an important public health achievement. GSK plans to make the vaccine available to the intended demographic before the 2023-2024 RSV season.

Pfizer is also developing an RSV vaccine for pregnant individuals to protect their children from the virus. AstraZeneca’s RSV vaccine for infants, known as Nirsevemab, is currently under FDA review. RSV is a common virus that can cause cold-like symptoms with mild severity. However, for those with weakened immune systems, particularly infants and older adults, RSV infections can become serious. The CDC estimates that annually, between 58,000 and 80,000 kids under five are hospitalized with RSV, between 60,000 and 160,000 seniors are hospitalized, and 6,000 to 10,000 die from the infection each year.

Last year, RSV was a contributing factor to the tripledemic, which included a sharp rise in cases of COVID-19 and the flu. Although children were the primary population affected, older adults also felt its impact, with higher-than-usual numbers being hospitalized from the illness. Until now, the primary prevention methods for RSV included washing hands regularly and often, avoiding close contact with others, and cleaning frequently-touched surfaces.

The approval of GSK’s RSV vaccine for adults is based on a randomized, placebo-controlled clinical study that’s still ongoing. It includes about 12,500 adults over 60 who received the one dose of the Arexvy vaccine, and an additional 12,500 who received a placebo. Participants saw an 82.6% reduced risk of RSV-associated lower respiratory tract disease and a 94.1% reduced risk of RSV-associated severe lower respiratory tract disease. However, there are a couple of possible side effects, including injection site pain, fatigue, and headache, which regulators will keep an eye on.

Additionally, in two smaller studies of adults over 60 who got the shot, one person developed Guillain-Barré syndrome, a rare disorder that damages muscles and nerve cells. Two others got acute disseminated encephalomyelitis (ADEM)—inflammation in the brain and spinal cord—after receiving the Arexvy shot concomitantly with an FDA-approved flu vaccine. One of those participants died.

Because of this, the FDA is asking GSK to assess possible signs of Guillain-Barré and ADEM in postmarketing trials, or studies conducted after FDA approval. The company will also look for possible risks of atrial fibrillation associated with the shot, as well.

In June, the CDC’s Advisory Committee on Immunization Practices will make further recommendations about appropriate use of Arexvy, GSK added, though the company is hoping to make the shot available before the 2023–2024 RSV season begins this fall.