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

The Beyfortus is available from Friday September 15 in France.

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

The Beyfortus is available from Friday September 15 in France. Intended for newborns, this new preventive treatment against bronchiolitis should help protect them from serious forms and reduce the number of hospitalizations.

[Updated September 15, 2023 at 2:42 p.m.] This should relieve health services. This Friday, September 15, 2023, marks the first day of the availability of a new preventive treatment against bronchiolitis: Beyfortus. This treatment, intended for newborns, aims to protect them from this respiratory infection. It was developed by the French laboratory Sanofi in partnership with the British AstraZeneca. Also called nirsevimab, it is an antibody which targets the respiratory syncytial virus (RSV), a virus "responsible for respiratory infections in newborns and infants which can transform into bronchiolitis", explains the High Authority of Health (HAS).

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,” further explains Aurel Guedj, emergency doctor at Ambroise-Paré hospital (AP-HP) to BFM TV.

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 in pharmacies. The HAS specifies, however, that Beyfortus “can only be prescribed and delivered on medical prescription” and that “to date, only doctors and nurses are authorized to administer it”.

If the treatment is intended for newborns, children born since February 6, 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. Please note that these dates only concern newborns in mainland France. Those of the overseas departments and regions will be communicated later.

The 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 severe forms of bronchiolitis – those that lead to hospital admission – is expected by Christophe Batard, a pediatrician who also participated in the development of the product and interviewed on 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, the 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 for 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 Minutes, Dr 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 from a hospital point of view”, including the large number of closed beds.