Germany's seven-day COVID-19 incidence rate has risen to 319 infections per 100,000 people due to the spread of the more contagious Omicron variants BA.4 and BA.5, the Robert Koch Institute (RKI) for infectious diseases said on Friday.

Axar.az reports citing the shares of the two subvariants BA.5 and BA.4 have doubled within one week to 10 percent and 2.1 percent, respectively, according to the RKI's latest weekly report.

The spike driven by the latest subvariants could also lead to an "overall increase in infection numbers and renewed infection pressure on vulnerable groups as early as summer," the RKI warned.

Available data on BA.4 and BA.5, however, did not point towards a more severe disease progression or more deaths than those registered with previous Omicron subvariants, according to the authority.

"We are not experiencing an infection-free summer this year, but that is not threatening for now," said Berlin Charite virologist Christian Drosten.