The U.S. Food and Drug Administration (FDA) approved the first-ever respiratory syncytial virus (RSV) vaccine for use in adults aged 60 and over on Wednesday.
The approval of its drug Arexvy is a major victory for British pharmaceutical giant GlaxoSmithKline (GSK), which has been rushing to get its RSV vaccine out to the market before competitors including Pfizer, Johnson & Johnson, and Moderna.
“Today marks a turning point in our effort to reduce the significant burden of RSV,” Tony Wood, GSK’s chief scientific officer, said in a statement, adding that the company will now focus on making sure eligible older adults in the United States can get the vaccine “as quickly as possible.”
The London-based company describes Arexvy as “generally well tolerated” with an “acceptable safety profile.” The most frequently observed adverse events associated with the product include injection site pain, fatigue, myalgia, headache, and arthralgia, which the company said were “generally mild to moderate and transient.”
Arexvy is what’s called an “adjuvanted vaccine,” meaning that it consists of both an RSV antigen, which is a subpart of the virus that prompts the immune system to produce antibodies that fight the disease and an adjuvant which helps generate a stronger immune response.
By contrast, the RSV vaccine candidates developed by Pfizer and Moderna are based on mRNA technology, meaning that they don’t contain any antigen or adjuvant, but instead instruct human cells to produce the virus protein that can trigger an immune response. Those candidates, namely Pfizer’s RSVpreF and Moderna’s mRNA-1345, are still under FDA review.
GSK had also been developing an RSV vaccine aimed at preventing the disease in pregnant women. In February 2022, however, it voluntarily called off enrollment and vaccination in its phase 3 maternal vaccine program because of safety concerns. This makes Pfizer’s RSVpreF the only remaining maternal RSV vaccine candidate.
The GSK shot is not currently approved anywhere outside the United States. The company said they’re working toward regulatory review and approval of the product in other countries.
Nearly all American children have been infected with RSV by age two, according to the National Institute of Health (NIH). In healthy people, symptoms of RSV infection are usually mild and resolve within a week.
“However, RSV can cause serious illness or death in vulnerable individuals, including premature and very young infants, children with chronic lung disease or congenital heart disease, and people who are over age 65,” the federal agency said.
In the United States, RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lungs) in children younger than one and causes approximately 58,000 hospitalizations among children under five annually, according to the NIH. It causes approximately 14,000 death of adults over age 65 each year across the country.
