The third phase of clinical trials of the SARS-CoV-2 coronavirus vaccine, developed by AstraZeneca and the University of Oxford, has been temporarily halted due to a possible dangerous adverse reaction in one of the patients. This is reported by Stat News.
Testing for the efficacy and safety of the AZD1222 vaccine has been paused to analyze data on side effects, according to a spokesman for AstraZeneca, one of the leaders in the race for the COVID-19 vaccine. An unexplained reaction in a test subject may not be related to the vaccine, but suspending studies is a routine process when vaccine-related illness is suspected. The trial participant is expected to recover, although his symptoms have not yet been reported.
AstraZeneca is going to conduct an expedited case analysis to minimize the delay in clinical trials. However, it is not yet clear how the situation might affect the availability of the vaccine. Nine vaccine candidates are currently in Phase III trials, and researchers working on other drugs have also begun looking for similar adverse events.
While it is still unclear how serious and rare the adverse event might be, it is likely to affect how quickly data from clinical trials conducted in the UK are published. Only this data will allow the FDA (Food and Drug Administration) to approve the release of a vaccine for emergency use.
In the second phase of the trial, 60 percent of the subjects (1000 participants in total) experienced side effects such as fever, headaches, muscle aches and tenderness at the injection site, but they were all minor. In the third phase of testing, about 30 thousand Americans will be involved.
AZD1222 was created on the basis of a neutralized adenovirus that causes the common cold, to which the gene of one of the SARS-CoV-2 proteins has been added. Similar adenovirus vaccines have already been tested against other dangerous viruses, such as the Ebola virus.
