Adam Niedzielski, who is at the forefront of the country’s battle against the coronavirus, said that from June 1 to Thursday, over 44,000 people had failed to turn up for their second shot.
He suggested that among the reasons for the rising trend were the falling number of fresh infections in Poland and the fact that the summer holiday season has begun, with Poles feeling less threatened by the virus.
With most of the vaccines administered in Poland, two shots several weeks apart are needed to ensure full protection.
More than 14.7 million people in Poland have been fully inoculated against COVID-19, the health ministry said on Friday.
Officials earlier in the day reported 76 new coronavirus infections and 17 more deaths related to the coronavirus, bringing the country's total number of cases during the pandemic to 2,880,670 and fatalities to 75,152.