■ Despite concerns across many countries, the AstraZeneca shot is proving effective in U.S.,

Astrazeneca Plc’s coronavirus vaccine fared better than expected in a U.S. clinical trial, providing reassurance about its safety and efficacy.

The shot developed with the University of Oxford was 79% effective in preventing COVID-19, and an independent monitoring board found no safety concerns, the company said Monday. All those immunized were protected from severe disease and death.

The findings should bolster confidence in the vaccine after confusion over its efficacy and the best dosing regimen slowed takeup. The product is at the center of a supply showdown with the European Union just days after concerns about blood clots prompted a dozen member states to suspend immunizations. Even after

the European Medicines Agency declared it safe last Thursday, not all EU countries have resumed vaccinations.

“Efficacy is better than we had expected,” said Peter Welford, an analyst at Jefferies in London. “Importantly, after recent largely unfounded safety concerns in Europe, the study confirms the safety profile.”

The company said it plans to submit the trial data to U.S. regulators in coming weeks, seeking clearance for emergency-use authorization.

A shortfall in deliveries to the EU has put Astra at odds with the bloc and led officials to oppose exports of the shot from the region as they seek to hold the company to account.

The new data offer more clarity than the first study results released last November. Those clinical trials, conducted in the U.K. and Brazil, produced a range of readings

due to different dosing amounts and regimens used. At least 10 EU countries only approved the shot for under-65s initially as early trials lacked older participants. Many have since reversed course after more data from realworld use showed the vaccine was effective for everyone.

Older adults made up about a fifth of the U.S. trial, which showed efficacy of 80% in that age group.

The results “offer confidence that adults of all ages can benefit from protection against the virus,” Ann Falsey, a professor at the University of Rochester’s School of Medicine and one of the trial’s lead investigators, said in a statement.