Polish Health Minister Adam Niedzielski warned that a fourth wave of the Covid-19 pandemic is likely to occur, probably in the second half of August.
Talking to Radio Plus on Tuesday, Niedzielski said that he expects a surge of cases similar to the one that is taking place in the UK, where the Delta variant has caused rising infection numbers, reports Xinhua news agency.
He added that indoor mask wearing will remain compulsory for the time being.
Niedzielski emphasised that while the Delta variant seems more infectious than previous mutations of the coronavirus, vaccines appear to prevent serious symptoms and hospitalisation.
He also said vaccinations will remain free of charge until at least September.
Poland has been gradually lifting restrictions put in place to contain the pandemic, with infection numbers falling and more citizens being vaccinated.
So far, 11.7 million Poles have been fully vaccinated, or 30.68 per cent of the total population.
The country has administered a total of 27,512,324 vaccine doses till date.
Since the pandemic began last year, Poland has registered 2,879,811 confirmed coronavirus cases, with 75,005 deaths.