In a statement, Britain’s Department of Health and Social Care said that the decision to approve the vaccine “follows months of rigorous clinical trials and a thorough analysis of the data” by a panel of experts who concluded that it met the standards for safety and effectiveness. Data previously released from large-scale clinical trials showed that the vaccine had nearly 95 percent efficacy and people who were immunized displayed no serious side effects.

Britain granted the emergency approval on Wednesday to the coronavirus vaccine developed by Pfizer and BioNTech, becoming the first country to do so. Distribution is expected to begin next week.

“Help is on its way,” British Health Secretary Matt Hancock tweeted on Wednesday. “The NHS stands ready to start vaccinating early next week.”

Approximately 800,000 doses are expected to arrive next week, with first priority going to nursing home residents and workers, and the most elderly citizens.

The Joint Committee on Vaccinations and Immunisations is expected to publish more details on its priority list later today.