SOFIA- Bulgaria has suspended the use of AstraZeneca's AZN.L COVID-19 vaccine for women below 60 years of age who are at an increased risk of thrombosis, its outgoing health minister said on Monday.

Bulgaria has inoculated some 638,400 people with a first dose of vaccine, about a third of them with the AstraZeneca vaccine, in one of the slowest vaccine rollouts in the EU.

"The AstraZeneca vaccine will not be administered to women below 60 years of age with an increased risk of thrombosis and/or diagnosed with thrombocytopenia," Kostadin Angelov told reporters.

Angelov said those people who have already received a first dose from AstraZeneca and did not experience any adverse effects should still get a second dose of the same vaccine.

Those who are unwilling to get a second dose from AstraZeneca may opt for a shot with a vaccine from Pfizer-BioNTech PFE.N some 84 days after their first, he said.

The Balkan country of 7 million people expects to receive more than 5.5 million doses of vaccine approved in the EU by the end of June, including 3.5 million from Pfizer-BioNTech, which will help it reach group immunity by the end of July, Angelov has said.

(Reporting by Tsvetelia Tsolova; editing by Jason Neely) ((tsvetelia.tsolova@thomsonreuters.com; +359-888-311-435;))