The Novavax vaccine is already authorized in other countries, notably in Europe and Canada.
In the United States, an independent committee convened at the request of the FDA is to meet on Tuesday to evaluate the data from the clinical trials of Novavax and to give its recommendation. Upstream, the agency published on Friday a long document analyzing these results, as it had done for the three other vaccines already authorized in this country.
In the aftermath, the title of Novavax collapsed by 20% on the New York Stock Exchange.
Novavax’s vaccine was found to be 90% effective against symptomatic cases of COVID-19 in trials conducted before the Omicron variant emerged, according to the FDA.
However, six cases of myocarditis, an inflammation of the heart muscle, were detected in the group that received the vaccine, against one case in the placebo group, the agency pointed out. Five cases occurred in the two weeks following vaccination.
The detection of several cases potentially associated with the vaccine
out of 40,000 clinical trial participants, raises the following concern: if a causal link exists, the risk of myocarditis following vaccination with NVX-CoV2373 could be higher than what has been observed during the post-authorisation period of messenger RNA vaccines
explained the FDA in its analysis.
Not enough proof
says the company
The risk of myocarditis has indeed been observed after vaccination with the Pfizer or Moderna vaccines, particularly in young men and adolescent boys. However, the FDA recalled that during clinical trials of these vaccines, no cases had yet been detected. She thus seems to be concerned that this risk is higher with the Novavax vaccine.
The company issued a response statement on Friday: We believe that there is insufficient evidence to establish a causal relationship
between cases of myocarditis and the vaccine, she said, adding that it was normal to expect to see a number of myocarditis
occur anyway within the population in any large enough database
.
