(CNN) After 60 years of scientific research, the world has the first vaccine to protect against respiratory syncytial virus, or RSV — and more is on the way.
On Wednesday, the US Food and Drug Administration approved Arxvy, which is made by GlaxoSmithKline and is designed to be given as a single injection to adults 60 and older.
It could be available to seniors as soon as this fall, pending a recommendation for its use from the US Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices, which meets this June.
Dr. Peter Marks, director of the FDA’s Biology Evaluation Center, said the research in a statement. “Today’s approval of the first RSV vaccine is an important public health achievement for preventing a potentially life-threatening disease and reflects the FDA’s continued commitment to facilitating the development of safe and effective vaccines for use in the United States.”
Although RSV is an illness most often associated with infants and young children, it can also be dangerous for the elderly. In the United States, an estimated 159,000 adults 65 and older are hospitalized each year with RSV, and an estimated 10,000 to 13,000 die as a result of their infection.
said Dr. Ruth Caron, professor of international health at the Johns Hopkins Bloomberg School of Public Health, who was not involved in vaccine development.
A pivotal discovery paves the way
In a clinical trial of nearly 25,000 older adults published in the New England Journal of Medicine, the GSK vaccine was 83% effective in preventing lower respiratory illness caused by the virus.
Lower respiratory disease was defined in the study as a positive test and two other symptoms for at least one day, including new or worsening cough, wheezing, shortness of breath, high respiratory rate, low blood oxygen or crackles in the lungs, which the physician had Captures with a stethoscope.
The vaccine was 94% effective in preventing severe disease in the elderly. People were considered to be very ill if they required supplemental oxygen or required mechanical assistance for breathing, such as a ventilator.
GSK’s RSV vaccine works by using a small piece of the virus: a protein that sticks to its surface called a fusion protein, or F protein, which helps the virus penetrate and infect cells in the body’s upper airways. The protein pieces in the vaccine are made in the lab using cells that are specially programmed to make them.
The vaccine builds on a pivotal discovery made a decade ago by researchers at the National Institutes of Health, including some of the same scientists who helped make Covid-19 vaccines.
Normally, the F protein is a wobbler, it flips back and forth, and changes shape after it fuses with a cell.
NIH researchers have figured out how to immobilize a protein in the form it takes before it is incorporated into a cell. In this form, the body can develop strong antibodies against it.
The GSK vaccine uses this active pre-fusion of protein, along with an ingredient called adjuvant, which boosts immune activity.
When researchers looked specifically at how well the vaccine worked in more vulnerable older adults — those with underlying health conditions such as chronic obstructive pulmonary disease, heart failure or heart disease — they found it was 94% effective at preventing lower respiratory infections.
“This is really exceptional information, because this is the kind of disease that we want to prevent. We want to prevent people from ending up in hospital with RSV,” said Dr. Lynn Friedland, director of scientific affairs and public health at GSK.
The most common side effects reported by people in the clinical trial included pain at the injection site and tiredness. It usually resolves within a day or two.
There were few serious adverse events in the study. They were balanced between the group that got the vaccine and the group that got the placebo, Friedland said. Friedland says researchers will continue to monitor for safety signals as the vaccine spreads to a larger population.
He said it was not clear exactly how protective the vaccine would be. The researchers will follow the study participants for three years and will continue to evaluate the vaccine’s effectiveness over time. So far, the protection seems to be holding up pretty well for about a year.
More RSV vaccines are on the way
Three other RSV vaccines for seniors are in the final stages of testing.
The US Food and Drug Administration (FDA) is expected to make a decision on Pfizer’s RSV vaccine for seniors by the end of May. The agency is also reviewing Pfizer’s maternal vaccine to protect infants and is expected to call in that vaccine by the end of August.
Moderna is completing its Phase 3 trial of an mRNA vaccine for RSV in the elderly and expects to submit the results to the FDA for approval within the next few months.
Bavarian Nordic, the manufacturer of the Jynneos mpox vaccine, says it will report results from a phase 3 trial of its RSV vaccine for seniors this year.
There’s a saying in Britain that you’ll wait a long time for a bus, and then four will show up at once, says Paul Chaplin, president and CEO of Bavaria Nordic. He says the race to the finish line for an RSV vaccine is a bit like.
“We’ve been waiting decades for a safe and effective RSV vaccine, and many attempts have failed,” Chaplin said.
“And I know GSK will probably get the first approval, but there are others that will come, including us. And I think it’s great, because RSV is a huge unmet medical need and a lot of people underestimate it, and we’re going to hopefully now that we have A number of effective vaccines that will help protect people.
Scientific triumph after tragedy
The search for an effective RSV vaccine is a story of scientific triumph over tragedy.
In the 1960s, two children died and several patients were hospitalized with severe RSV when experimental vaccines they were given were shown to promote infection rather than defend it off.
That study tested a vaccine made from the RSV virus that had been chemically treated to make it inert and mixed with an ingredient called alum, to wake up the immune system and help it respond.
It was tested at clinical trial sites in the United States between 1966 and 1968.
At first, everything seemed fine. The vaccine was tested on animals, which tolerated it well, and then given to children, who also seemed to respond well.
Unfortunately, when the RSV season began that fall, many more vaccinated children required hospitalization and became sicker with RSV than they would normally have.
A study of the trial found that 80% of vaccinated children who later became infected with RSV required hospitalization, compared to only 5% of children given a placebo. Two of the young participants in the experiment died.
The results were a seismic shock to vaccinology. Efforts to develop vaccines and treatments against RSV stalled when researchers tried to solve the problem.
Many of the barriers currently placed around vaccine clinical trials stemmed from the failures of the RSV vaccine.
The scientific breakthrough that allowed scientists to freeze the virus’s F protein in place also allowed NIH scientists Dr. Jason McClellan and Barney Graham to stabilize the spike protein of the coronavirus, accelerating development of a Covid-19 vaccine.
“RSV has taken us a while to unravel its mysteries and mysteries,” said Dr. Stephen Varga, dean of the Graduate School of Biomedical Sciences at St. Jude Children’s Research Hospital, who has spent his career studying the virus. and designed a vaccine against nanoparticles.
“It’s a really exciting time. It’s been a long time,” he said.
Minnesota resident Tanya Richter wishes a vaccine was available for her grandfather Adam Kasman, a retired school bus driver who died after a severe bout with RSV last summer. He was 95 but otherwise healthy and living in Jamestown, North Dakota, when his RSV tore his elbow.
He was taken to hospital and later recovered enough to be discharged to a nursing home, but Richter said it was the beginning of the end for him. He died a few weeks later.
“He was a great grandfather. I haven’t gotten to see him much in the last couple of years, just with Covid, who was trying to keep everyone safe, kept that from happening,” she said.
“I really wish it was around before that happens because vaccines give us a fighting chance,” she said. “Hopefully, you will save someone else’s grandfather.”