The French National Authority for Drug Safety did not find “any risk factor” in the drug “Beyfortus”, which is intended to protect infants with antibodies against bronchiolitis and has been available for a year to parents of newborns, according to a report published on Monday about its initial assessment of the possible presence of side effects. harmful to him.
The authority noted, in a statement about the first preventive immunization campaign, that 244,495 doses of “Befortus” from the company “Sanofi” were given to infants in maternity hospitals and outside them between September 11, 2023 and April 30, 2024, of which 198 cases were reported. Related to drug safety.
The authority explained that “the vast majority (74.7%) of the 198 cases reported were related to the effectiveness or ineffectiveness of “Befortus,” and the recording of respiratory syncytial bronchiolitis in children who received the antibodies.”
She added, “No specific risk factor was detected after taking Bifortus in these children who developed bronchiolitis of varying degrees of severity (there were no deaths).”
The nercevimab molecule that makes up Bifortus is not a vaccine, although it is an injectable. Rather, it is a preventive treatment that prevents the main virus that causes bronchiolitis, respiratory syncytial virus, from infecting the organism.
This drug is intended as a vaccine, but the principle is different, as its mission is not to cause the body to develop antibodies to the respiratory syncytial virus, but rather to inject the virus directly.
The authority noted “cases of respiratory disorders and general toxic effects after injections (such as influenza syndrome, decreased appetite, and decreased muscle strength) were reported, all of which developed in a positive manner.”
She added, “A single stroke case was also reported,” but explained that “the causal relationship between Bifortus and these effects has not been proven” yet.
These potential repercussions will be subject to specific monitoring by the regional drug safety centers and the national authority, according to the statement.
The authority considered that “these results, in addition to the studies conducted regarding effectiveness, generally confirm the positive balance between the benefits of Bifortus and its risks.”
Respiratory syncytial virus
An epidemic of bronchiolitis affects children every year, mainly due to respiratory syncytial virus, which generally circulates from October to February.
Although the disease is most often mild, some infants suffer from more serious cases that require hospitalization.
However, the situation has changed since the approval of preventive treatments, especially “Bifortus”, which is based on synthetic antibodies.
In addition to the French studies, two studies conducted in Luxembourg and Spain in recent months showed that this drug significantly reduced the risk of children being hospitalized due to bronchiolitis.
In France, the children’s immunization campaign for next winter, which was launched in mid-September, is based on “Befortus” for newborns and children under one year of age, and more recently on “l’Abrysvo” from Pfizer. For pregnant women.