we verified three claims about Beyfortus and the respiratory infection that affects babies

The bronchiolitis immunization campaign began in mid-September, but it is targeted by strong misinformation on social networks.

It is a very official-looking brochure, with logos and polished graphics, which is shared a lot on social networks, while the bronchiolitis immunization campaign began in mid-September. Its title: “Important reminders about bronchiolitis and Beyfortus. Beyfortus is optional and potentially dangerous”. This document is not official, in reality. It was created by the Parents et Citoyens France collective, a collective rather opposed to vaccines founded after the Covid-19 pandemic, in particular to request the lifting of vaccination obligations for children, and which speaks out against Beyfortus, the preventive treatment given to babies to reduce the risk of developing serious forms of bronchiolitis.

1 Is Beryfortus “dangerous”?

The brochure states that the preventive treatment against bronchiolitis, which is injected by injection, but is not a vaccine, is “dangerous”. However, this is not the case. Several studies demonstrate precisely the opposite. The last one was published on September 30. The National Medicines Safety Agency (ANSM) took stock of the first Beyfortus immunization campaign, in the winter of 2023-2024, which affected 240,000 children. The ANSM has no identity “no particular risk factor” related to treatment.

In its brochure, the anti-vax collective also claims that mortality due to Beyfortus treatment is higher than mortality due to bronchiolitis, which is also false. No mortality due to treatment has been established, while mortality linked to bronchiolitis is 2.6 per 100,000 babies. The collective draws this conclusion from the so-called Mélody study, published in March 2022, as part of a clinical trial to test the effectiveness and safety of nirsevimab, the immunization agent which makes up Beyfortus. This study reported three deaths among the thousand babies who had received the treatment, but no link had been established with the treatment, as reported by AFP Facteur.

Similarly, last winter, the ANSM recorded the deaths of three babies out of the 240,000 who had received the treatment but, once again, no causal link with Beyfortus was established.

2 Is Beyfortus ineffective?

The brochure from Parents and Citizens France ensures that Beyfortus “does not reduce the number of hospitalizations”although it is false. At least two studies published during the summer by Public Health France demonstrated that preventive treatment was effective against severe forms of bronchiolitis.

According to the first study, Beyfortus reduces the risk of need for intensive care for babies with this acute respiratory infection by 75%. According to the second study, thanks to preventive treatment, between 3,700 and 7,800 babies avoided hospitalization due to worsening bronchiolitis.

3 Isn’t bronchiolitis a “public health problem”?

The collective still affirms that “bronchiolitis has always affected a minority of infants, without being a public health problem (…) it is generally benign” and that, “despite a few rare trips to the emergency room, mortality is barely 0.0026%, according to Public Health France”.

The mortality estimate given in the brochure is good. It is 0.0026% or 2.6 babies per 100,000. However, it is false to say that bronchiolitis is not a public health problem. Almost a third of babies under the age of two suffer from bronchiolitis each winter and 2% to 3% are hospitalized because of a severe form. Before the arrival of Beyfortus, Public Health France had counted 73,000 visits to the emergency room due to bronchiolitis during the winter of 2022-2023, which had overloaded services.