Pharmaceutical company AstraZeneca will put an experimental coronavirus vaccine study on hold in America after a participant in the United Kingdom faced an apparent serious adverse reaction. The pause is “a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials. A suspected serious adverse reaction includes symptoms that require hospitalization, life-threatening illness and even death. It was also not immediately clear which clinical trial the adverse reaction occurred in. A Phase 1/2 study published in July reported about 60% of 1,000 participants on the vaccine experienced side effects. The AstraZeneca vaccine, known as AZD1222, was invented by the University of Oxford and an associated company, Vaccitech.
The monoclonal antibodies are derived from the convalescent plasma of COVID-19 patients. AstraZeneca only began its Phase 3 trial in the U.S. in late August. The U.S. trial is currently taking place at 62 sites across the country. Phase 2/3 trials were previously started in the U.K., Brazil, and South Africa. The Oxford vaccine uses a type of virus called an adenovirus to teach the immune system how to make antibodies to attack the coronavirus’ so-called spike protein. It’s that spike protein that allows the virus to infect human cells.