After 60 years of trial and error, the Food and Drug Administration (FDA) approved the first vaccine to prevent respiratory syncytial virus (RSV) on May 3. More preventative shots for the respiratory virus are on the way.
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The FDA approved Arexvy from pharmaceutical company GSK. The vaccine is designed to protect those over 60 in a single dose. A vaccine from Pfizer is currently under consideration for older adults and pregnant people as a maternal vaccination to protect newborn babies. Sanofi and AstraZeneca’s monoclonal antibody treatment for babies that offers vaccine-like protection during RSV season is also under consideration by the FDA. Additionally, a late-stage trial of an RSV vaccine that uses mRNA technology from Moderna showed promise in late-stage trials.
The vaccine could be available as soon as this fall, pending a recommendation for its use from the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices, which will meet in June. GSK says it has “millions of doses ready to be shipped,” according to a recent earnings presentation.
“Older adults, in particular those with underlying health conditions, such as heart or lung disease or weakened immune systems, are at high risk for severe disease caused by RSV,” said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, in a statement. “Today’s approval of the first RSV vaccine is an important public health achievement to prevent a disease which can be life-threatening and reflects the FDA’s continued commitment to facilitating the development of safe and effective vaccines for use in the United States.”
RSV can affect all age groups, but it is particularly worrisome in babies and older adults. It is a highly contagious virus that causes infections of the lungs and breathing passages. According to the Centers for Disease Control and Prevention (CDC), RSV leads to approximately 60,000 to 120,000 hospitalizations and 6,000 to 10,000 deaths among adults 65 years of age and older every year. It is also a common cause of lower respiratory tract disease in older adults. This disease affects the lungs and can cause life-threatening pneumonia and bronchiolitis.
The virus circulates seasonally, usually beginning in the fall and peaking in the winter. The 2022-2023 RSV season started particularly early and flooded hospitals and pediatric wards across the United States, leading pharmacies to limit the sales of children’s medicines.
According to the results of a clinical trial of close to 25,000 older adults, the GSK vaccine was 83 percent effective at preventing lower respiratory tract disease by the virus. It was 94 percent effective at preventing severe disease in seniors. In the trial, severe disease was defined as the need for supplemental oxygen or a mechanical help to breathe. The results were published in the New England Journal of Medicine in February.
[Related: Fighting RSV in babies starts with a mother’s antibodies.]
The vaccine works by using a small piece of the virus called a fusion protein, or F-protein. The F-protein sticks out on the virus’ surface and helps it latch onto cells in the upper airway and infect them. The F-proteins were made in a lab with specially programmed cells.
In 2013, researchers at the National Institutes of Health discovered how to freeze the normally wiggly and shape-shifting F-protein in the shape that it takes before it fuses onto a cell. When it’s in this shape, the body can produce antibodies against it. The GSK vaccine uses this pre-fusion form of the F-protein and an ingredient called an adjuvant that can boost immune activity.
The search for a vaccine to RSV began in the 1960s, but has been mired by tragedy. Two toddlers died after receiving an experimental shot in the 60’s after it unexpectedly caused them to contract a very serious version of the virus. Many of the safety measures currently in place during vaccine trials were put in place after the failures of the RSV vaccine.
Barney Graham, a vaccine scientist at Morehouse School of Medicine worked alongside Jason McLellan, a structural biologist at the University of Texas at Austin, and Peter Kwong, a vaccine scientist at the National Institutes of Health, to jump-start the RSV vaccine field after decades of failure.
“This is my life’s work, so it’s kind of amazing to see it come to this point,” Graham told The Washington Post. “It’s exciting for me to see this happening because of all the other people who’ve come before me working on RSV, some of whom are no longer with us. I wish they could see this is happening. It’s been a long struggle.”