AstraZeneca

The head of the European Union's executive arm has announced plans for a major contract extension for COVID-19 vaccines with Pfizer.

The European Medicines Agency placed no new restrictions on using the vaccine in people 18 and over. The agency says based on the available evidence, it was not able to identify specific risk factors.

Updated study results say the vaccine is 76% effective against symptomatic COVID-19 and 100% effective against severe disease. Independent monitors had been concerned about a previous report.

In an unusual post-midnight statement, the National Institute of Allergy and Infectious Diseases said AstraZeneca might have used old data for its COVID-19 vaccine trial.

Results of the trial, which involved more than 32,000 volunteers, showed two doses of the vaccine administered four weeks apart had an efficacy of 79% at preventing symptoms of COVID-19.

"Its benefits continue to be far greater than its risks," said Dr. Sabine Straus of the agency's risk committee. It found no increase in the overall risk of blood clots with the vaccine.

Several other countries including France, Germany, the Netherlands and Ireland moved to suspend injections of the vaccine this week.

The two countries joined a number of other European nations that have temporarily suspended the shot after several people reportedly developed blood clots after receiving it.

A study raised concerns about its effectiveness against the coronavirus variant sweeping through the country — although the data is too preliminary for definitive conclusions.

The pharmaceutical company made the announcement on Monday, saying that one dosing regimen showed the vaccine was 90% effective in preventing infection.