The first round of Covid-19 vaccinations for group 2 frontline workers got underway in Fiordland this morning.

Medical staff, ambulance, fire and police officers lined up to receive their first dose of the Pfizer vaccine from 8am at the Fiordland Medical Centre in Te Anau.

Over 65s and those with pre-existing medical conditions will be called up from May. They are group 3. The general population will have to wait until July to receive their first vaccination.

Under 16 year olds remain ineligible to receive the vaccine.

Covid-19 response Minister Chris Hipkins and Director General of Health Dr Ashley Bloomfield gave a Covid-19 update this afternoon, saying there were two new cases in managed isolation but none in the community.

So far more than 135,585 doses of the Pfizer vaccine have been given to people in New Zealand, with one million expected to be delivered over the next 12 weeks.

This week, 34,378 people have received their first dose, with 43 percent of those in Auckland.

Medsafe had given approval for Pfizer's vaccine to be stored for up to two weeks at -20C before it is used or returned to -70C.

Bloomfield says this will help with transporting the vaccine to more remote areas.

There are two freezers in Christchurch, which are not be used yet, and 315,000 doses of the vaccine in Auckland freezers, which have a capacity for 760,000 doses. More freezers are on order and should be ready before the end of June.

A security guard who tested positive for Covid at the Auckland's Grand Millennium MIQ hadn't been tested since November, it was revealed in today's update.

It appears he was supplying incorrect information to his employer. All his close contacts have tested negative, however.

Hipkins says: "With any system that involves thousands of people, there is a risk of issues at the margin. That appears to be the case here."