Health officials in Germany say the coronavirus reproduction number, or R-number, has jumped to almost 1.8.
That's the highest value since the middle of March and means the virus is almost doubling in the rate that it spreads.
The increase has been caused by localised outbreaks, with most of the cases in northwestern Germany where more than 1000 people working at a meat-processing plant tested positive.
Berlin correspondent Thomas Sparrow speaks to Philippa Tolley.