As of 1 May 2022 all COVID-19 related travel restrictions for entry to Bulgaria from other countries have been lifted. From this date on, all the arriving passengers are no longer obliged to provide COVID-19 related documents (i.e., COVID-19 vaccination certificates, COVID-19 recovery certificates, COVID-19 medical examinations) in order for them to be allowed to enter the territory of the Republic of Bulgaria.
Additional information on the measures taken in Bulgaria can be found on the website of the Ministry of Health: https://www.mh.government.bg/en/.