For nearly 50 years, scientists have been trying to develop the best vaccine to protect against the respiratory syncytial virus, or RSV.
But they haven’t made significant headway until the last couple of years when current trials showed very promising results.
“We already knew that it gave you a really good immune response,” said Dr. Edward Walsh, infectious disease specialist for UR Medicine. “But what we now know is that immune response translates into it prevents infection.”
Walsh and his research team have been leading the way for Pfizer’s bivalent RSV vaccine, which fuses proteins from two major RSV strains for a more robust immune response.
Vaccine trials involving infants and people older than 60 have been conducted since 2020. Results showed the vaccine is 66.7% effective at preventing general illness, 85.7% effective at preventing lower respiratory tract infection with three or more symptoms, and 62.1% effective at preventing acute respiratory infection.
“We’re very pleased,” Walsh said.
The data also showed that the immune response passed from a mother to a baby was about 70% effective in preventing severe infection for the first three months of the baby’s life.
Although RSV is not a novel virus, the effect it had on the health care system this past season, after being effectively dormant during the COVID-19 pandemic, brought a heightened awareness of the disease.
“It's almost like the virus came back with a vengeance in a way,” Walsh said, “My perspective, that's great -- so people now know about it.”
Walsh said unlike the mRNA technology used to create the COVID-19 vaccine, the one used for RSV is “more old school” and “standard” -- like the flu shot. He hopes that will lead to more public acceptance.
“This is a pretty routine, straightforward approach,” Walsh said, “So hopefully, that will help people feel more comfortable.”
He said the only notable side effect is soreness near the injection area.
Walsh said, unlike COVID and flu, RSV is not constantly evolving, which means the vaccine will not have to be manipulated and re-injected seasonally. However, it is strong enough to evade the immune system more frequently than most viruses, causing multiple re-infections. Walsh said this vaccine may prevent that.
“This vaccine just simply is unopposed by the immune system, and you get a very good response,” Walsh said, “So it may work better than actually getting infected.”
The advisory panel for the U.S. Food and Drug Administration has reviewed the data from Walsh’s trial and has voted to recommend approval by the administration. Walsh said this approval may come as soon as late summer or early fall.
