The European digital Covid certificates of 93,000 Bulgarians, whose vaccination course was completed more than 270 days ago, end on February 1 and will not be valid for travel in the EU, according to the Ministry of Health. The reason is that from this date on the documents proving the completed vaccination course will be valid for 270 days from the date of the last dose. Booster dose certificates are not limited by the EC with a validity period. The requirement applies only when traveling within the European Union.