Coronavirus infections are rising exponentially in Germany, an expert at the Robert Koch Institute for infectious diseases said on Tuesday, putting at risk plans to lift the lockdown and revive the economy.

The number of cases per 100,000 reported on Tuesday was 83.7, up from 68 a week ago, and the RKI has said that metric could reach 200 by the middle of next month.

Germany is in a third wave of the pandemic, driven by an easing of restrictions in recent weeks just as a more transmissible variant has spread, Dirk Brockmann, an epidemiologist at the RKI, told Germany's ARD television.

"It has been totally irrational to loosen up here. It is just fueling this exponential growth," he said.

Chancellor Angela Merkel and state leaders agreed a phased easing of curbs earlier this month along with an "emergency brake" to let authorities reimpose restrictions if case numbers rise above 100 per 100,000 on three consecutive days.

They are due to meet again on March 22.

The city-state of Berlin has decided to stop any more easing, such as allowing restaurants or cinemas to open, the Tagesspiegel newspaper reported.

Germany's decision on Monday to suspend AstraZeneca's vaccine could delay progress in reaching herd immunity, analysts said.

Of the 60 million vaccine doses scheduled for the second quarter, almost 17 million are from AstraZeneca, the head of the KBV family doctors' association Andreas Gassen told the Handelsblatt newspaper.

"Even if it is only a temporary stop, it will be more difficult for family doctors to start vaccinating," he said.

The decision follows seven cases of thrombosis in Germany, including three deaths, and deals a heavy blow to efforts to speed up a sluggish vaccination campaign. 

A planned meeting between Merkel and state leaders on Wednesday to discuss using family doctors to administer COVID-19 vaccines has been postponed until after the European Medicines Agency completes a review into the AstraZeneca shot.

The German talks will probably happen on Friday, said Rhineland-Palatinate state Premier Malu Dreyer.