Berlin,  Daily Covid-19 infections in Germany recorded a sharp increase as 8,324 new cases were registered within one day, 3,328 more than one week ago, the Robert Koch Institute (RKI) said on Wednesday.

The last time that new infections within 24 hours exceeded 8,000 was during the third wave in mid-May. After the situation had calmed down for a while, new infections in Germany have been rising since the beginning of July, the Xinhua news agency reported.

The country's vaccination campaign slowed down considerably recently and Germany's virologist Christian Drosten issued a clear warning to unvaccinated people.

"Those who do not get vaccinated will get infected, and perhaps as early as this winter," he told German press agency dpa on Wednesday, Xinhua reported.

Due to the particularly contagious nature of the Delta variant and the fact that vaccinated people could pass on the coronavirus too, unvaccinated people could no longer hope for protection through herd immunity.

"Everyone, in particular those 45 and older, is strongly advised to take a very serious look at whether they really do not want to be vaccinated," Drosten said.

More than 48.1 million people in Germany were fully vaccinated as of Wednesday, bringing the country's vaccination rate to 57.8 percent, according to the RKI, the federal government agency for disease control and prevention. More than 52.8 million Germans received at least one dose.

The incidence rate of reported Covid-19 cases in Germany in the past seven days per 100,000 citizens also continued to rise and reached 40.8 on Wednesday, up from 37.4 the previous day and 25.1 a week ago, according to the RKI.

To date, more than 3.8 million COVID-19 infections have been officially registered in Germany since the outbreak of the pandemic. The death toll climbed to 91,921 on Wednesday, said the RKI.