The COVID-19 vaccine co-developed by Oxford University and AstraZeneca was one of the first vaccines that were announced and to complete clinical trials.
Unlike the Pfizer-BionTech and Moderna vaccines, the one developed AstraZeneca did not need extreme storage conditions and could be stored in ordinary freezers.
This made the AstraZeneca COVID-19 vaccine more acceptable and affordable around the world.
But it has not been a smooth sail for the vaccine or AstraZeneca ever since.
The company has been at odds with the EU for failing to live up to its vaccine commitments and at one point was facing an export ban.
Now adding to its troubles are the reports of side-effects. The most serious one that has been reported so far is blood clots, which have forced many countries to stop administering vaccines to their people.
Though AstraZeneca continues to stand by its claim that its vaccine is safe, there is more worrisome news.
The UK medical regulator said Saturday that out of 30 people who suffered blood clots after receiving the Oxford-AstraZeneca vaccine, seven have died.
The UK's Medicines and Healthcare products Regulatory Agency said in a statement that "Out of the 30 reports up to and including 24 March, sadly 7 have died."
The UK regulator said that the 30 reports of thrombosis, submitted by medics or members of the public via a government website, came after 18.1 million doses of the vaccine had been administered in the country.
Most of the cases (22) were cerebral venous sinus thrombosis, a rare condition when a blood clot forms in the brain.
Eight other cases saw people suffer thrombosis and low levels of blood platelets, which help blood clot.
There were no reports of blood clots from the Pfizer/BioNTech vaccine it said, adding that "our thorough review into these reports is ongoing."
The regulator's website says that on the basis of current data, the benefits of the vaccines against COVID-19 "continue to outweigh any risks".