The evidence on the fatality rate is worrisome but not yet solid, scientists said. It contrasts with news that Britain is vaccinating its people at a promising pace.
For many Christmas was only the beginning, Day 1 of a high-stakes and unpredictable experiment in how to unstitch a tight web of commercial relations across Europe.
The U.K. and the European Union struck a trade deal Thursday, setting the terms of their commercial relations after Britain completes its hard-fought split from the EU on Dec. 31.
Doses of the Pfizer-BioNTech vaccine will be injected starting next week, the government said.
Scientists said a series of irregularities and omissions in the way AstraZeneca initially disclosed the data have eroded their confidence in the reliability of the results.