The country's top health official today reiterated a dire warning that New Zealand should brace for a second wave of Covid-19 to sweep through the community, similar to the outbreak wreaking havoc in Victoria.

Director general of health Dr Ashley Bloomfield said the health ministry had been sounding the warning about the prospect of community transmission in recent weeks and was now gearing up for the likely prospect.

It's been more than three months since the last case of Covid-19 was contracted in the community. In the past 95 days all Covid infections have been detected and contained at the border as ill people return to New Zealand. There are currently 22 active cases in quarantine.

While life has returned to near normal for the majority of Kiwis, across the ditch a fresh deadly wave of Covid-19 has seen a state of disaster declared in Victoria with strict lockdown rules and mandatory mask-wearing across the state.

The New Zealand Government this week relaunched a campaign to raise community awareness of Covid-19, instructing people to "be ready" and take a test when they were given the opportunity.

"We don't want to end up like Melbourne and there's no room at all for complacency, that's why we've got all our planning and preparation going full steam ahead," Bloomfield told Newstalk ZB's Mike Hosking Show.

"We've got everything in place we think minimises the risk down to as low as possible but there are still hundreds of people still working in the facilities and working at the border.

"So far we have been successful but remember that is where the cases came from in Victoria which has led to this huge outbreak.

"This is a tricky virus and we just have to be very vigilant. Part of that is doing testing in the community to detect any infection that might get through as quickly as possible."

He claimed contract tracing was in good shape with a large-scale test run planned in a couple of weeks' time. Testing capacity was now above 3000 cases a day.

However, Bloomfield said while the health agencies were prepared for the next wave it was down to Kiwis to do their part.

"We need to be fully prepared - and that's everybody, not just the health sector.

"When we last had the outbreak here, some of the people who were being looked after in hospital by people trained in the use of PPE [personal protection equipment], we still saw some breaches of people who were using full PPE. The virus is not straight forward. It's tricky."

He said there were very tight processes in the managed isolation and quarantine facilities to prevent the spread of disease.

He said the ministry was undertaking audits of the facilities to make sure the staff were all using PPE.

"Our infection control is good. So we're doing everything we can but part of keeping New Zealand safe is to do surveillance testing. It's a core part of our programme."