Britain on March 22 demanded the European Union allow the delivery of Covid-19 vaccines the country has ordered as tensions over a possible export ban on EU-manufactured shots mounted and Brussels pointed an accusing finger at drugmaker AstraZeneca.

Fewer Europeans trust the AstraZeneca Covid-19 vaccine after several countries reported side effects, such as blood clots, an opinion poll by YouGov showed on March 22, even though scientific studies have found it is safe and effective.

Scientists are exploring several possibilities that might explain at least 18 reports of extremely rare blood clots in the brain that occurred in individuals in the days and weeks after receiving the AstraZeneca COVID-19 vaccine.

Europe pushed to get its Covid-19 vaccination drive back on track on March 19 after EU and British regulators said the benefits of AstraZeneca’s shot outweighed any risks following reports of blood clots.

Vaccitech, which partnered with AstraZeneca and Oxford University on the development and manufacturing of that company’s Covid-19 vaccine, raised $168 million in a Series B financing round that will be used to support development of its own lead candidates in oncology and infectious disease.

A World Health Organization (WHO) vaccine safety panel said on March 17 that it considers that the benefits of the AstraZeneca Covid-19 vaccine outweigh its risks and recommends that vaccinations continue.

The World Health Organization appealed to countries on March 15 not to pause vaccination campaigns after two more European nations and one in Asia joined a handful which suspended use of AstraZeneca’s Covid-19 vaccine over safety fears.

AstraZeneca Plc said on March 14 a review of safety data of people vaccinated with the company’s Covid-19 vaccine has shown no evidence of an increased risk of blood clots.

Multiple countries across Europe and parts of Asia suspended the use of AstraZeneca’s Covid-19 vaccine over fears the medication is leading to the development of blood clots in some patients who have received the medication.

Six former FDA commissioners – Scott Gottlieb, Robert Califf, Mark McClellan, Margaret Hamburg, Jane Henney and Andrew von Escehenbach – signed a joint letter urging the U.S. president to nominate a permanent commissioner soon.