viruses

Dubai, United Arab Emirates (CNN) — After a 60-year scientific career, the world now has the first vaccine to prevent respiratory syncytial virus (RSV), and more vaccines are under study.

On Wednesday, the US Food and Drug Administration approved Arexvy, manufactured by GlaxoSmithKline (GSK), designed to be given as a single dose to adults over 60 years of age.

It may be available to the elderly this fall, with its use to be recommended by the CDC’s Immunization Practices Advisory Committee at its next meeting, scheduled for next June.

“Older adults, especially those with underlying health conditions, such as heart or lung disease or a weakened immune system, are at increased risk of serious illness,” Dr. Peter Marks, director of the FDA’s Center for Vaccine Evaluation and Research, said in a statement. caused by the respiratory syncytial virus.

The approval of the first RSV vaccine is an important health achievement for preventing potentially fatal disease, and reflects the FDA’s continued commitment to facilitating the development of safe and effective vaccines for use in the United States, Marks said.

Although RSV is a disease most often associated with infants and young children, it can pose a risk to the elderly.

In the United States, about 159,000 people age 65 and older are hospitalized each year with RSV, and about 10,000 to 13,000 people die from the virus.

RSV is certainly an important disease for older adults, with nearly as many people infected as influenza in this age group in some years, according to Dr. Ruth Caron, professor of international health at the Johns Hopkins School of Public Health, who was not involved in vaccine development.

A crucial discovery paves the way

In a clinical trial involving 25,000 older adults, the results of which were published in the New England Journal of Medicine, the respiratory syncytial virus (RSV) vaccine was 83% effective in preventing lower respiratory tract infections. that is caused by the virus.

Lower respiratory tract disease was defined in the study as a positive test and two minimal symptoms, including severe cough or rapid breathing, labored breathing, increased respiratory rate, low blood oxygen, or wheezing in the lung. which the doctor can detect with a stethoscope.

The vaccine was 94% effective in preventing severe disease in the elderly.

Participants were considered severely ill if they needed supplemental oxygen, or if they needed mechanical assistance for breathing, such as a ventilator.

The RSV vaccine works by using a small part of the virus, a protein on its surface called an integrin, or chaperone, that helps the virus attach to and infect cells in the body’s upper respiratory tract.

The protein pieces in the vaccine are made in a lab using cells specially programmed to make them.

The vaccine builds on a discovery made a decade ago by researchers at the National Institutes of Health, including some of the scientists who helped make COVID-19 vaccines.

Normally, the F protein is wobbly, bouncing back and forth, and changing shape after fusion with the cell.

A vaccine uses this pre-fusion form of the protein, with a component called an adjuvant, which boosts immune activity.

And when the researchers looked specifically at how effective the vaccine was in the most 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 in preventing lower respiratory infections. .

“This is really exceptional information, because this is the kind of disease that we want to prevent. And we want to reduce the number of people who end up in hospital with RSV,” said Dr Lyn Friedland, Director of Scientific Affairs and Public Health at GlaxoSmithKline.

The most common side effects reported by participants during the clinical trial include injection site pain and tiredness, which usually improve within a day or two.

There were few serious side events in the study. Friedland explained that it was distributed between the group that got the vaccine and the group that got the placebo.

He said researchers will continue to watch for safety signals while the vaccine is rolled out to a wider audience.

The US Food and Drug Administration said it has asked GlaxoSmithKline to continue monitoring for signs of Guillain-Barre syndrome, a neurological disorder that can cause paralysis or weakness that rarely occurs after viral infection and vaccination.

It also asked the company to study the risks of a condition called acute disseminated encephalomyelitis, a rare type of inflammation that affects the brain and spinal cord.

And the Food and Drug Administration reported that two people in clinical trials of the vaccine experienced this condition after receiving the dose with the influenza vaccine.

It is not known exactly how strong the vaccine’s protection is, according to Friedland.

The researchers will follow the study participants for three years and will continue to evaluate the effectiveness of the vaccine over time. So far, the protection seems to last well for about a year.