Washington (AFP)

The American pharmaceutical giant Johnson & Johnson wanted to be reassuring Tuesday on the suspension considered "temporary" of its clinical trial for a vaccine against Covid-19 after the unexpected illness of a participant.

"We have temporarily suspended additional dosing in all of our clinical trials of an investigational vaccine against Covid-19, including the entire Phase 3 trial, due to unexplained illness in one participant," said announced the group in a press release.

The group learned of the participant's illness on Sunday evening and announced it on Monday evening, management said.

Consequence: no more participants in the trial receive the vaccine or the placebo until further notice.

An independent expert committee will study the data to see whether or not the "unexplained disease" may or may not be related to the vaccine.

The management of the group insisted on the "temporary" nature of this pause: "Our plan is to continue the study", indicated the research director for the group, Mathai Mammen during a conference call presenting in addition the third quarter financial results.

He said it would take "a few days" before more information was available on what caused the participant's illness.

He could not say, in response to a question, whether the alleged disease was neurological in nature.

In such studies, he added, the occurrence of an unexpected illness "may or may not have something to do at all with the drug or vaccine being studied."

- "Not rare" -

CFO Joe Wolk was also reassuring: "Pauses are not uncommon if you think of the vaccine trial we are conducting."

"These are 60,000 individuals, it's a big study," he said, adding that on trials of this magnitude, "we should expect that there would be a suspension for an adverse event. ".

The recruitment of volunteers for phase 3 of the Johnson & Johnson clinical trials began at the end of September, in order to engage 60,000 participants at more than 200 sites in the United States, and in other countries.

Johnson & Johnson, which has promised to sell its future vaccine against Covid-19 without making a profit, is one of ten groups around the world to conduct phase 3 trials, and the 4th in the United States.

Its vaccine candidate is based on a single dose of an adenovirus, which causes the common cold, modified so that it cannot replicate and combined with a part of the Sars-CoV-2 coronavirus called the spike protein (or "spike" ) that it uses to enter human cells.

For now, Johnson & Johnson say they are waiting for the diagnosis from the Drug Oversight Committee.

He says, according to his financial director Joe Wolk, does not know if the sick participant was included in the sample of those who received a placebo or those who received the vaccine injection.

"We let the security protocols follow the proper procedure and we just have to wait for new information," said the official.

- Reassure the public -

"This should reassure the public that all scientific, medical and ethical standards are applied (...) while we are all looking for a vaccine to fight Covid-19", added the leader.

Last September, clinical trials of the candidate vaccine against Covid-19 developed by AstraZeneca and the University of Oxford, considered one of the most promising, were also interrupted after a British participant developed an unexplained pathology .

These trials resumed in Japan in early October but not in the United States where the pharmaceutical giant says it is working with the drug authority.

Two phase 3 trials, led by Pfizer and Moderna, are still ongoing in the United States.

Announced shortly before the presentation of quarterly results, the disappointment of Johnson & Johnson weighed down the stock, which fell by more than 2% around 3:40 p.m. GMT on Wall Street, despite a big profit and optimism for the whole year .

The group posted a net profit of 3.5 billion dollars for a turnover of 21.08 billion dollars, up 1.7%.

Johnson & Johnson has also raised its annual forecasts.

© 2020 AFP