BERLIN (REUTERS) - The more infectious Delta coronavirus variant will become dominant in Germany by the autumn at the latest, the country's top public health official said on Friday (June 18), urging the public both to continue wearing masks indoors and to get vaccinated.

"The Delta variant makes up about 6 per cent of infections, but its share is growing," Dr Lothar Wieler, head of the Robert Koch Institute for infectious diseases said, referring to the variant first identified in India.

"It is not a question of if Delta will become dominant but a question of when," he added. "It will have the upper hand in the autumn at the latest."

Germany's 16 states have started easing restrictions in place since last November which, coupled with an accelerating vaccination campaign, had helped the country tame a third wave of coronavirus infections.

The seven-day incidence per 100,000 residents stood at 10 on Friday when just over 1,000 new cases and 91 deaths were reported.

Restaurants, bars, beer gardens, hotels and concert halls have reopened, a development welcomed by many Germans as the lifting of restrictions coincided with hot weather and the approach of the summer holidays.

Health Minister Jens Spahn said some 51 per cent of Germans have had at least one of the two vaccine shots required for effective protection against the virus and around 30 per cent have had both shots.

Germany holds a national election in September and the accelerating vaccination campaign after a sluggish start as well as the lifting of lockdowns have lifted support for Chancellor Angela Merkel's conservatives in opinion polls.

The conservatives are polling on some 28 per cent, eight points ahead of their nearest rival, the ecologist Greens.