BERLIN — The head of Germany’s disease control agency says the vaccination rate needs to increase to avoid another wave of the coronavirus, warning “the pandemic is not over yet.”

Lothar Wieler of the Robert Koch Institute says Germany could experience another wave in cases in the fall, with the potential of overwhelming the country’s health system. On Wednesday, the institute reported 13,565 confirmed cases.

While infection rates have been stagnant in recent days, the number of hospitalizations has increased in Germany. The number of patients in intensive care has almost doubled to more than 1,300 in the last two weeks, Wieler says.

Most hospital patients are younger than early in the pandemic and the majority aren’t vaccinated. Wieler says everyone who doesn’t get vaccinated likely will contract the virus at some point in the pandemic.

More than 61% of the population are fully vaccinated in Germany. That’s less than in several other European countries.

There’s been more than 4 million confirmed cases and 92,448 confirmed deaths in Germany since the start of the pandemic.