The vast majority of genome copies were in the emerging JN.1 subvariant. (file image) Photo: RNZ / Dom Thomas
The latest Covid-19 wastewater figures show a sharp decline over the past two weeks.
Surveillance figures from the Institute of Environmental Science and Research (ESR) suggest the most recent Omicron wave is tailing off.
The ESR tracks the presence of Covid-19 in wastewater around the country.
The most recent wave appears to have peaked in the first week of January at 8.46 million genome copies per person per day.
Since then the viral load has dropped by more than half, down to 3.76 million GC/p/d in the week ending 21 January.
The vast majority of genome copies were in the emerging JN.1 subvariant, which has risen from 14.3 percent of genomes at the start of December to 70.8 percent in the latest data.
The seven-day rolling average of genome copies detected in wastewater, along with reported cases, is also down from its most recent peak of 1100 in the second week of January to 957 cases last week.
University of Canterbury Professor Michael Plank said he was "cautiously optimistic" the country was moving out of its fifth Covid-19 wave.
"In terms of the overall trend, I'd say we've been on an extended plateau for the last couple of months."
Professor Plank said hospitalisations had also followed the downward trend.
The latest figure was 343, down from a peak of 400 at Christmas, he said.
"It's still relatively high compared to the levels that we saw throughout most of last year, but it is significantly below the peak level that we saw last Christmas."
He added that wastewater detection could vary, especially over the summer holiday period.
"Auckland's been very variable - perhaps as a consequence of people moving around the country over the holiday period."
Despite this, he said the data pointed to the country leaving the fifth wave.