The surge in coronavirus infections due to the fast-paced spread of the omicron variant is expected to peak in a week, a top Israeli health official said.

“In the coming week, we will still see increasing numbers, but in another week we will start to see a decline,” Health Ministry Director General Nachman Ash said in an Army Radio interview on Tuesday. “There are another two or three difficult weeks ahead.”

There have been about 50,000 new cases of coronavirus confirmed daily in the past few days, and the number of severely ill patients has climbed to about 500, Ash said.

Israel is currently offering a fourth dose of the Pfizer vaccine to older adults, medical personnel and people at risk. Ash said health officials weren’t surprised by preliminary data from a trial that showed that a fourth dose raises antibodies substantially, but doesn’t provide effective protection against infection from omicron. Health officials believe older adults and those at risk should get a fourth dose, because it may provide protection against severe illness, Ash said.

Israel started rolling out the fourth dose to over-60s and immunocompromised in late December amid a surge in cases. Since then, more than half a million Israelis have received the extra dose, according to the Health Ministry.