How does Beyfortus, the new treatment for bronchiolitis, work?

How does Beyfortus the new treatment for bronchiolitis work

A new preventive treatment against bronchiolitis intended for babies is available in France from Friday September 15. The product should help prevent serious forms of bronchiolitis and eight out of ten hospitalizations.

[Mis à jour le 15 septembre 2023 à 10h30] It is available from Friday September 15, 2023 in French health establishments: Beyfortus. Developed by the Sanofi and AstraZeneca laboratories, this new treatment is supposed to protect newborns against bronchiolitis as winter approaches. Beyfortus, or nirsevimab, is an antibody that acts against the respiratory syncytial virus (RSV), considered to be the main cause of bronchiolitis.

Unlike a vaccine, which helps the immune system to produce antibodies, this new treatment consists of directly injecting antibodies into the body of infants for immediate protection against the virus and lasting for six months. “We don’t teach him to protect himself, but we give him the weapons to defend himself,” adds Aurel Guedj, emergency doctor at Ambroise-Paré hospital (AP-HP) with BFM TV.

A single injection from birth

The Beyfortus treatment for bronchiolitis consists of a single injection made into the muscle, more precisely into the child’s thigh, the days following birth. Newborns born after September 15, 2023 should all be “immunized before leaving the maternity ward”, according to the recommendations made by the Ministry of Health to caregivers. Treatment is made available in hospitals, pediatric wards, health centers and general practices. It is also available to order in pharmacies.

If the treatment is intended for newborns, children born earlier in 2023 can also receive Beyfortus antibodies. The idea with this treatment is to protect each child before their first winter, when they are most vulnerable to RSV.

Between 75 and 80% of serious cases of bronchiolitis avoided

Preventive treatment against bronchiolitis has proven itself with “more than 83% effectiveness against hospitalizations” according to Charles Wolf, vaccine manager at Sanofi France who worked on the development of the treatment, contacted by France info. A similar effectiveness of 80 to 85% against serious forms of bronchiolitis – those which lead to hospital – is expected by Christophe Batard, pediatrician who also participated in the development of the product and questioned about BFM TV. Doctor Aurel Guedj estimates that with the treatment, “there are 25% fewer hospitalizations” for infants suffering from bronchiolitis.

Although it does not always prevent the disease from contracting, treatment helps protect babies against bronchiolitis in the majority of cases and prevents the development of serious forms in eight out of ten cases. Ultimately, it should lead to the unclogging of hospitals and pediatric services during the winter.

In fact, this Beyfortus preventive treatment against bronchiolitis should help prevent a repeat of the situation we experienced last winter. At the time, 73,262 children under the age of two were taken to the emergency room for bronchiolitis and 26,104 were hospitalized after a trip to the emergency room, reports Public health France (SPF). The epidemic was in fact “characterized by a very high intensity, almost twice higher than the average values ​​of reference epidemics”, indicates SPF. In the columns of 20 minutesDr Anne Béguin, pediatrician and member of the French Association of Ambulatory Pediatrics, even affirmed that last winter had been a “catastrophe”, evoking the “virulence of the epidemic” but also the “difficulties of a hospital point of view”, including the large number of closed beds.