New Zealand is battling a new wave of the Omicron strain that is disproportionately impacting the senior population, and the country is seeing COVID-19-related deaths at historic rates.

According to Health Ministry data, there were 151 deaths caused by the virus in the seven days leading up to July 16, up from 115 in the worst week of the last wave in March. The ministry announced on Friday that 26 patients with COVID died in the past 24 hours, all of whom were older than 60.

The Omicron BA.5 sub-variant is driving the current wave in New Zealand, which has 5.1 million people. There have been 64,780 active cases in the past seven days, although authorities say many infections are unreported.

Once regarded as a model for preventing COVID infection, New Zealand’s swift response to the pandemic and its geographic isolation kept it largely free from the virus until the end of last year.

The government dropped its zero-COVID policy this year once the population was largely vaccinated. Since then the virus has been allowed to spread.

Emergency departments, general practices and medical centres are under pressure. However, Health Ministry data shows hospitalisation levels remain below those seen during the March peak.

The government is resisting pressure from some doctors to reinstate curbs on public gatherings or mandate the wearing of masks at schools.

However, Education Ministry chief Iona Holsted said on Thursday the ministry had advised schools to enforce the wearing of masks as much as practicable when children returned from holidays next week.

“We understand that implementing mask policies can be a challenge but ask that you take action to strengthen your mask wearing policy as soon as possible,” she said.