The first-ever vaccine against the common winter bug Respiratory Syncytial Virus has been approved by the Food and Drug Administration.
Arexvy was more than 84 percent effective against lower respiratory tract infections and 94 percent effective against severe disease in clinical trials.
It works by exposing the immune system to proteins from the surface of the virus, triggering the mass manufacture of antibodies.
Respiratory Syncytial Virus (RSV) kills about 10,000 American adults every year and can also cause severe disease among young children. Scientists have struggled to develop a vaccine against it for decades amid multiple failed trials.
The first-ever vaccine against a common winter virus has been approved by the Food and Drug Administration (stock image)
The FDA gave the green light today for the vaccine to be administered to adults aged 60 years and older.
It will now need to be recommended for use by the Centers for Disease Control and Prevention (CDC) before it can become available to the public. This is expected to come next month at an advisory meeting.
It was not clear whether approval would be extended to children, but there are other RSV vaccines in development for the age group. One being made by Pfizer is expected to be approved later this year.
Developed by British pharmaceutical giant GSK, Arexvy is administered as a single dose to patients to spark protection.
It targets only one of two versions of RSV, RSV A, but studies show it sparks virtually equal protection against both strains.
The FDA approval was based on a study of 25,000 patients who received either Arexvy or a placebo.
The study is due to run for three RSV seasons, with approval based on data from the first year of the research.
It was not clear whether participants may later be offered boosters.
Side effects of the injection included pain at the injection site, fatigue, muscle pain, headaches and joint stiffness.
Ten vaccine recipients also suffered atrial fibrillation, or an irregular heartbeat.
In two other studies on the vaccine, two participants had brain inflammation and one suffered from Guillain-Barre syndrome, a rare disorder in which the body’s immune system damages cells.
Announcing the approval of the drug Dr Peter Marks, an FDA director, said this was an ‘important public health achievement’.
GSK has said it is now ready to start supplying the vaccine to the US market, and is also ready to start sending doses to other countries.
It is expecting approval from the UK, European Union, Canada and a number of other countries in the coming months.
Work on an RSV vaccine has been haunted for decades following multiple failures in clinical trials.
This includes one study in the 1960s where children who received an experimental vaccine experienced worse disease than those in the placebo arm. Two youngsters, both under the age of two years, died.
Research later found that this was because the vaccine had targeted a version of the protein on the virus that forms after it fuses to a cell, meaning it did not trigger protection against the disease and may have actually hampered the immune response.
RSV infections generally surge in the fall up to the end of spring.
In adults, the virus generally causes a cold with symptoms including a runny nose, loss of appetite, cough and fever.
But in older adults and those with weaker immune systems it can trigger a lung infection that leads to pneumonia.
The virus returned with a vengeance this year amid an absence of Covid restrictions allowing infections to rebound.
Dr Marks said: ‘Older adults, in particular those with underlying health conditions such as heart or lung disease or weakened immune systems, are at higher risk for severe disease caused by RSV.
‘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.’