Clinical trials for the COVID-19 vaccine developed by AstraZeneca and Oxford University have been put on hold after a participant developed a suspected adverse reaction, Stat News first reported.
But don’t worry; this is exactly how clinical trials are meant to work. The decision to pause the trial also doesn’t mean the vaccine caused the adverse event; the side effect could have occurred by chance in someone who received the vaccine.
The pharmaceutical company AstraZeneca “voluntarily paused vaccination to allow review of safety data by an independent committee,” a company spokesperson said in a statement. “This is a routine action that has to happen when there is a potentially unexplained illness in one of the trials.” In large clinical trials with thousands of participants, “illnesses will happen by chance,” but each illness must be independently reviewed to uncover whether the reaction was at all related to the vaccine, the spokesperson added.
The participant who developed an unexplained illness is enrolled in a phase 2/3 trial based in the U.K., according to a person familiar with the situation who spoke with The New York Times on the condition of anonymity. (Phase 2/3 trials look at how the immune system responds to a vaccine and whether vaccinated people have a lower chance of catching COVID-19 than unvaccinated people, while also monitoring for side effects, Live Science previously reported.) Details on the individual’s illness are not yet known, but the participant is expected to recover, a person familiar with the matter told Stat News.
“This is the whole point of doing these phase 2, phase 3 trials,” Dr. Phyllis Tien, an infectious disease physician at the University of California, San Francisco, told The Times. “I think halting the trial until the safety board can figure out whether or not this was directly related to the vaccine is a good idea.”
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AstraZeneca is one of nine drug companies to publicly pledge that they will not release a coronavirus vaccine without adequate safety and efficacy data from “large, high-quality clinical trials,” The New York Times reported Sep. 8. In recent weeks, President Donald Trump has teased that a COVID-19 vaccine could be available before election day, raising concerns from scientists and health officials that a vaccine might be released without clear proof that it’s safe and actually works.
“I love the fact that the nine big vaccine manufacturers … said they would not do anything premature,” Dr. Judith Feinberg, the vice chairwoman for research in medicine at West Virginia University, told The Times. “I think there’s enormous pressure to do something premature.”
Originally published on Live Science.