On Wednesday, the Food and Drug Administration approved The first vaccine to protect against respiratory syncytial virus, also known as respiratory syncytial virus.
This is a crucial moment in the fight against catastrophe. Researchers have been working to develop an RSV vaccine for more than half a century. And it’s no exaggeration to say that an RSV vaccine could save hundreds of thousands of lives worldwide each year.
RSV commonly causes cold symptoms, but can also cause severe lung inflammation and infection in very young and very old people.up to each year 160,000 hospitalizations and 10,000 deaths among older Americans, and 55,000 adult deaths Globally. People with heart or lung disease and weakened immune systems are most at risk for severe RSV disease.
The RSV season usually begins in autumn and is worst in winter. The vaccine, known as Arexvy, is approved for adults 60 and older and will likely be recommended by the CDC in June, making it available in time for people to get it this fall. It’s a schedule. report in the New York Times.
Young babies, especially those born prematurely, are also at increased risk of ill health from RSV. Each year, the virus causes up to 80,000 hospitalizations and 300 deaths for her children under the age of five in the United States, and 2 million outpatient visits.Viruses also lead to estimates 120,000 infant deaths around the world every year.
Currently, this news has not impacted the pediatric community. But there is hope. Several vaccines that protect babies and children, and many others for adults, are currently under FDA review or in early stages of development.
RSV was the main cause of the “triple infection” that flooded hospitals last winter. If these vaccines hit the market, the cold and flu season could turn around dramatically.
For now, here’s what you should know:
Vaccines are highly effective and generally have mild side effects
Arexvy, made by pharmaceutical company GSK, is one of two adult RSV vaccines reviewed by the FDA on March 1. meetingIn trials, the vaccine nearly reduced the risk of lower respiratory tract disease in adults over the age of 60 83 percentand the risk of severe illness is 94%.
Administered in a single injection, the vaccine is constructed using conventional technology that predates the mRNA technology used to create many Covid-19 vaccines. It is built using chunks of the RSV virus and some additional molecules. The result is called a. recombinant vaccine This is because it combines fragments of the virus with other products that stimulate the immune system. Other vaccines built with this technology include those used to prevent whooping cough, meningitis, and shingles.
Side effects associated with the vaccine were generally mild and resolved within 1-2 days. The most common side effects were mild to moderate pain at the injection site, and a few people reported fatigue after the injection.
FDA monitors serious side effects
In most cases, the Arexvy vaccine appears to be safe. However, the FDA is paying attention to some rare side effects as more people get the vaccine. It’s as serious as it deserves.
In one trial with 12,500 participants in each group, 10 Arexvy recipients and 4 who received a placebo experienced atrial fibrillation (an irregular, rapid heartbeat that causes blood clots to form in the heart). heart rhythm). (condition is very common Among the elderly, it is sometimes reversed. If it doesn’t go away, it can be treated with blood thinners. ), one of her participants in the trial developed Guillain-Barré syndrome, a condition in which the immune system attacks nerve cells, causing weakness and sometimes paralysis.
In another trial of 2,500 people each in the Arexvy and placebo groups, two of the vaccine recipients developed an inflammatory condition affecting the brain and spinal cord, one of whom died.
The FDA is asking GSK to monitor the occurrence of all these conditions among future vaccinated people.
As always, the question for government agencies is whether the risk of vaccine side effects is greater than the risk of RSV. Time will help answer that question.
This is a big win!
People started trying to develop an RSV vaccine in the 1960s. Why did it take so long to get it working?
The RSV surface protein is a shape-shifter and adopts different morphologies depending on whether it has entered or fused with human cells. To make things even more complicated, their pre-fused shapes are highly unstable. So for a long time, researchers’ only option was to use the protein’s post-fusion form as a target for new vaccines.
As a result, for many years the RSV vaccine failed to recognize viral particles because They got into cells — too late to make a big difference. To make better vaccines, scientists really need a clear picture of what those surface proteins look like. There was Before cell invasion.
In 2013, structural biologist Jason McClellan, now at the University of Texas at Austin, found a way to get that image. He devised a way to stabilize surface proteins in their pre-fusion form., then explained it in great detail. This discovery has enabled researchers to create a vaccine that targets the early stages of his RSV infection.
Arexvy is only the first downstream result of this discovery to be approved by the FDA, with more results likely to follow soon. Pfizer’s adult-use RSV vaccine is likely to be approved later this month. Moderna said it expects its adult vaccine to be approved in the first half of this year. Several companies are working on vaccines to protect babies and young children under the age of two.
Overall, we expect more good news about RSV vaccines in the near future.
