Would the Janssen vaccine be less effective in fighting severe forms of Covid-19? The National Medicines Safety Agency (ANSM) underlines a “significant number” of cases of vaccine failure.
“An alert was relayed by two regional pharmacovigilance centers (Marseille and Tours) concerning the overrepresentation of patients vaccinated by Janssen in intensive care”, indicates the agency in its update on the surveillance of vaccines against the coronavirus. “A potential signal has been highlighted in the presence of a large number of cases of vaccine failure with the Janssen vaccine, with patients in intensive care or who have died from Covid-19, most of whom have serious risk comorbidities.”
A little over a million injections have been carried out since April with the single-dose serum produced by Johnson & Johnson laboratories. Among all these vaccinated people, 32 cases of Covid-19 infection were identified, including 29 serious cases and 4 deaths recorded. Health authorities identified the variant responsible for the infection in 17 people, and each time it was the Delta variant.
In view of these elements, the ANSM will carry out “additional investigations”, in particular to check whether these “failures” are more frequent or serious with Janssen than with other anti-covid vaccines sold on the market.
On August 24, the French National Authority for Health (HAS) recommended that people who have been vaccinated with Janssen be injected with a booster dose with a messenger RNA vaccine (Pfizer or Moderna), at least four weeks after their vaccination. “The available data do not confirm the long-term efficacy of the vaccination schedule at one dose of the Janssen vaccine against the Delta variant”, explained the HAS at the time.