For the time being, AstraZeneca stopped research into a corona vaccine after a test subject turned out to have a serious condition. According to Dutch scientists it is good news that the “safety procedures are being followed”, but it also means that the development of the vaccine may be delayed by months.
AstraZeneca’s vaccine is one of the six vaccines that may come onto the market in the Netherlands, and one of the few that is already being tested in a Phase 3 study. A total of 300 to 400 million of these vaccines have been reserved by the European Union, the first vaccines of which are expected to be on the market in Europe by the end of this year at the earliest. Whether or not this will succeed is now even more uncertain.
As soon as an unexplainable condition is found in participants for whom the vaccine has been tested, it must be reported to an external committee that supervises the study. That committee has now decided to halt the investigation and will find out whether there is a link between the vaccine and the disorder. If there is no such link, the committee can give permission to restart the research.
“It shows that, despite the pressure to do everything as soon as possible, all normal safety procedures are followed,” says Ingrid Schellens, of the Medicines Evaluation Board. As soon as AstraZeneca wants a license for the European market, it must assess the vaccine on behalf of the Netherlands as clinical assessor,
According to her, it is not uncommon for vaccines and medication to be temporarily halted when there is a report of a disorder with an unknown cause.
Thousands of people
Professor of vaccinology Anke Huckriede agrees with her. “The more people take part in a study, the more likely it is that something like this will happen.” The drug has recently been tested on thousands of people in Brazil, the United States, South Africa and the United Kingdom.
“This only shows that they take safety very seriously,” concludes Professor of Immunology Marjolein van Egmond. “This is just a safety measure.”
In the New York Times, an anonymous source says a participant was found to have an acute inflammation of the spinal cord, myelitis transversa. Such an inflammation could be caused by a viral infection, but could also be the result of administering a vaccine.
Weeks or months of delay
If this is indeed myelitis transversa, then according to Professor Huckriede this is a serious setback that can cause a long delay. “Then it’s definitely several weeks, if not months.” The external committee must then try to prove that it has nothing to do with the vaccine.
According to Schellens there are three possible outcomes. The investigation can be restarted if there seems to be no connection or if the person in question appeared to have received the placebo. It may also be that one has to go back to the pre-clinical phase of the research, in order to test on animals again. In theory, the research could also be stopped if there is a clear connection with the condition.
The British health minister, Matt Hancock, was cautiously optimistic today. According to him, it doesn’t have to affect when the vaccine comes on the market. “It’s a challenge,” he said.