AstraZenecaAstraZeneca (NYSE:AZN) has resumed its COVID-19 vaccine trial in the U.K. following confirmation from the Medicines Health Regulatory Authority (MHRA) that it was safe to proceed.

The news of the trial resumption, announced Sept. 12, came six days after a voluntary pause so that an independent committee could review safety data surrounding a single event of an unexplained illness. The person with the illness was part of the Phase III  trial for the AZD1222 vaccine AstraZeneca is developing in collaboration with Oxford University.

Now that the trial has resumed, AstraZeneca declined to disclose further information.

AstraZeneca is one of nine drug companies that have pledged to ensure safety with a potential COVID-19 vaccine and only submit for approval or emergency use authorization (EUA) after demonstrating safety and efficacy through a Phase 3 clinical study. The companies made the pledge amid worries that there is political pressure in the U.S. to release a vaccine against the pandemic before Election Day on Nov. 3.