Experts in Germany have slammed Health Minister Karl Lauterbach for saying that a "killer variant" of COVID-19 could catch the country unaware later this year.

"The term 'killer variant' is unscientific and leads to nothing but uncertainty among the population," virologist Jonas Schmidt-Chanasit told the German Bild newspaper.

"According to the World Health Organization, the occurrence of a 'killer variant' in the autumn is a very unlikely scenario," the expert said.

Virologist Hendrik Streeck also reacted with skepticism, saying that the development of variants was simply impossible to predict.

"Instead of warning about scenarios like 'killer variants,' it is important to prepare for autumn and winter," he told Bild.

In an interview with Sunday's edition of Bild, Lauterbach expressed concern about the unpredictable development of omicron subvariants.

"It is quite possible that we will get a highly contagious omicron variant that is as deadly as delta: That would be an absolute killer variant," the politician said.