Earlier this week, the United States Food and Drug Administration approved a new medication for the prevention of respiratory syncytial virus (RSV) in infants.
Spread through coughs and sneezes, RSV is an upper respiratory virus that most severely affects young children, older adults, and those with immune, lung or heart conditions. In these populations, the virus spreads to the lower respiratory systems, which can lead to much more severe breathing difficulties. It’s estimated that RSV is responsible for 11% of hospital admissions for infants in Canada, over seven times that of the flu.
The medication, known as nirsevimab and found under the brand name Beyfortus™, is a human recombinant monoclonal antibody— a protein made in a lab that resembles those made in the body in response to an infection. They attach to foreign substances, like viruses, and stops them from functioning so that other immune cells can attack and remove them. This is a preventative treatment to be administered to infants and children experiencing their first two RSV seasons (typically in autumn).
Unlike the currently used antibody, palivizumab (brand name: Synagis®), this new medication is significantly cheaper to produce and requires only one dose every five months, as opposed to monthly injections.
In trials, nirsevimab was tolerated well, showing few adverse effects compared to a placebo, with the most common reactions being a rash at the injection site.
The drug was approved for use in children under two years old, and has also been approved for use in Europe, though the Canadian Agency for Drugs and Technologies in Health (CADTH) has not yet assessed it for use in Canada.