The US Food and Drug Administration (FDA) has approved the first treatment for preventing severe respiratory syncytial virus (RSV) infections in children and infants.
RSV is a common virus that circulates in the autumn and winter. Most children with RSV usually experience mild, cold-like symptoms, but some – especially those exposed to the virus for the first time – can develop life-threatening respiratory diseases such as pneumonia and bronchiolitis.
The treatment, called Beyfortus, is a single dose given by injection before or during a baby’s first RSV season. Children up to 2 years old who remain vulnerable to RSV during their second RSV season, such as those with chronic lung or heart disease, are also eligible for the shot.
Approximately 1 to 3 per cent of children under 1 year old are hospitalised for RSV each year in the US, according to the FDA. Last year saw a notably bad RSV season as hospitals nationwide struggled to keep up with the surge in cases, which caused medication shortages.
“RSV can cause serious disease in infants and some children and results in a large number of emergency department and physician office visits each year,” said John Farley at the FDA’s Center for Drug Evaluation and Research in a statement. “Today’s approval addresses the great need for products to help reduce the impact of RSV disease on children, families and the health care system.”
Beyfortus, manufactured by the pharmaceutical company AstraZeneca, is not a vaccine. Instead, it uses monoclonal antibodies against RSV. These are proteins engineered to mimic the antibodies produced by the immune system to fend off harmful pathogens. Unlike a vaccine, it does not train the body to identify RSV or produce its own antibodies in response to infection. Side effects include rash and pain, swelling or redness at the injection site.
The FDA made its decision based on data from three clinical trials, which included almost 4000 infants. In these trials, a single dose of Beyfortus reduced the risk of infants needing medical care for an RSV infection by between 70 and 75 per cent.
Earlier this year the FDA approved two vaccines against RSV for older adults. Later this year, the agency is also set to decide on a maternal RSV vaccine, which would protect newborns from the illness.