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 suggest the most recent Omicron wave is trailing 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 per cent of genomes at the start of December to 70.8 per cent 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.

- RNZ