Wave ‘might be peaking’

If Covid-19 cases hold steady into early next week, it will be a ‘‘clear sign’’ New Zealand is approaching the peak of its second Omicron wave, a modeller says.

Aotearoa is in the midst of a second wave, fuelled by the more transmissible BA.5 subvariant. As of this week, BA.5 accounted for half of community cases and this was likely higher given the lag in sequencing.

While daily case numbers appeared to have remained relatively steady, every day the seven-day rolling average had been up on the same day the previous week, Te Pu¯ naha Matatini modeller and University of Canterbury professor Michael Plank said.

Cases were still going up but appeared to have slowed down a bit, which Plank said was ‘‘good news’’. If this trend continued into the beginning of next week, that could indicate New Zealand was potentially getting close to a peak. If this was the case, this could also mean cases would peak at a level lower than was feared, he said.

Modelling indicated cases could get to a comparable level as in the first Omicron wave, at about 21,000 cases per day.

That said, it is not known how many tests are being done or how many cases are being missed.

On Thursday, Director-General of Health Dr Ashley Bloomfield said there were probably ‘‘double’’ the number of cases in the community compared with what testing is showing. Border surveillance testing and wastewater showed a ‘‘significant’’ increase in Covid-19 across all regions in recent weeks.

Plank said it was possible that because more cases would be reinfections, people might not realise they needed to test again, which could be contributing to a drop.

Just shy of 4% of cases, in the 24 hours to 1pm yesterday, were reinfections.

It was also possible this week was a ‘‘blip’’ – with school holidays potentially impacting test behaviours and cases (however, cases in school-aged children were relatively low at the moment), Plank said.

In the week ending July 10, there had been a 33% increase in the number of cases in over 65s – a group that was not as impacted in the first Omicron wave. This spike in cases in older age groups was driving the increase in hospitalisations.

Plank said the fact that hospitalisations continued to rise – albeit slightly slower than some of the large jumps seen in recent days – was important, particularly as older people were most affected.

‘‘It is certainly possible, even if cases peak well below the level they did in March, that hospitalisations could still be on par with the first wave, or higher, because of that older age shift.’’

Yesterday, the seven-day rolling average number of Covid-positive people in hospital was 700, up from 499 the same day last week. If no further interventions were taken, hospitalisations are modelled to peak at about 1200 per day, according to one Ministry of Health scenario, but could be brought down to about 950 a day if we take steps to limit exposure to the virus, officials advised this week.

The number of cases in those over 70 is more than double that in the first Omicron wave, which was heavily concentrated on younger people. As a result, many older people were less immune as they had not had Omicron yet, Plank said.

Plank said it was great news rapid antigen tests were now more accessible, with the Government yesterday removing the eligibility criteria that people needed to be symptomatic or household contacts to get kits for free.

If people planned on visiting an older person, he urged them to test using a RAT beforehand to assess their risk.