Four Bulgarians vaccinated against the Coronavirus (COVID-19) with the Pfizer/BioNTech vaccine developed mild to moderate side effects, Bulgarian Drug Agency executive director Bogdan Kirilov said on Monday.

Bulgaria’s vaccination campaign began on Dec. 27 among the priority group including medical workers.

By Monday, nearly 5,000 people had been inoculated.

“Side effects ranged from mild to moderate.

The persons who experienced them have already recovered,” Kirilov said, as quoted by the Bulgarian National Radio.

According to the official, the side effects included two cases of pain, one case of dizziness, and one case of insignificant temperature rise.

Earlier in the day, Bulgaria received the second shipment of the Pfizer/BioNTech vaccine, consisting of 25,000 doses.

According to Health Minister Kostadin Angelov, the mass vaccination in Bulgaria would likely begin sometime in the February-March period. (Agency report)