State health officials on Thursday reported a continuing drop in new coronavirus cases, as the Boston-area COVID wastewater data keeps plunging — an encouraging sign that the omicron variant is quickly retreating.

Both the south and north of Boston COVID wastewater data have now plummeted by 86% since the omicron peak in early January. The regions’ average levels are now comparable to before the holiday surge.

The sewage data is the earliest indicator of future COVID cases in the community, and the most recent update from the wastewater tracker signals a continuing dive in infections.

Thursday’s daily count of 8,616 new virus cases in Massachusetts was significantly down from last Thursday’s report of 14,384 infections. That’s a 40% decline week-over-week.