The supply cuts delayed the EU's vaccination drive in the first quarter of the year, when the bloc had initially bet on AstraZeneca to deliver the largest volume of its shots.
The court said in a statement that AstraZeneca must deliver 15 million doses by July 26, another 20 million by Aug. 23 and another 15 million by Sept. 27, for a total of 50 million doses.
Britain also cut its order for the single-dose shot, also known as J&J unit Janssen's vaccine, amid issues with the company's supply chain and reports of rare blood clots.
J&J's vaccine is already approved in the United States and European Union, where reports of rare blood clots are being reviewed.
*The 67-year-old, who had contracted the coronavirus in January, said he wanted to encourage all older adults to also get vaccinated. "We're sure there is no risk, no danger, that there are no serious side effects," he said.
A government statement late on Tuesday said a task force had determined that the AstraZeneca vaccines already available in the country presented no risks to the population.
The European Medical Agency (EMA) is due to announce the results of a review on whether some cases of blood clotting in adults may be linked to the AstraZeneca shot.
South Korea's food and drug safety ministry said on Wednesday it had granted final approval for Johnson & Johnson's (J&J) vaccine after a panel of experts ruled the single-dose shot was safe and effective.
Ukraine received its first batch of 215,000 Sinovac doses in March to boost its vaccination programme, which has lagged behind many other European countries and it has so far relied on a single batch of AstraZeneca vaccines from India.
"The vaccines of the Chinese company Sinovac Biotech can be trusted," it said.
The decision was made following new reports from medicine monitoring agency Lareb and discussions with health authorities, a Health Ministry statement said.
"Authorities in the UK, European Union, the World Health Organization have concluded that the benefits of using our vaccine to protect people from this deadly virus significantly outweigh the risks across all adult age groups," it said.
EU lawmaker Peter Liese, from the same party as German Chancellor Angela Merkel, said the report left him speechless, and he urged AstraZeneca to clarify the situation.