There are zero new cases of Covid-19, Director General of Health Ashley Bloomfield says.

The total number of confirmed and probable cases since the pandemic began sits at 1503.

One person is in hospital in Auckland's Middlemore and five more people have recovered. Ninety-six per cent of all cases have recovered, he said.

Bloomfield encouraged Kiwis to download the NZ Covid Tracer app which was made available last night.

"The app is another tool in our toolbox [to contact trace]."

The app has the function to scan QR codes at participating businesses so users can keep a digital log of their movements without needing to handover their personal details to businesses.

The only information held at the Ministry is the contact information you provide when you register, other records of where you've been is only stored on the phone, he said.

The app helps "build a picture" of where you've been if you're infected with Covid-19/
92,000 people have downloaded the app.

The Ministry of Business Innovation and Employment is also contacting 800,000 businesses and already 1000 have downloaded QR code posters and more are being registered are at a rate of 10 per minute.

Issues with the app are being worked through, he said.

Bloomfield said any uptake of the app was "good and helpful" and the more the better as it helped with contact-tracing.

Privacy had been a major consideration of the app and had been worked through with the Privacy Commissioner, as would any future iterations which have Bluetooth functionality, he said.

Bloomfield said if he personally were to check into a cafe, he would probably just use the one app.

It's hoped the app would eventually take the place of manual sign-ins at businesses.

Anyone who's using fake details when signing into businesses should understand the purpose of providing their details, said Bloomfield.

Bloomfield said there was a "good incentive" for businesses to sign up to the app and move from a manual sign-in as it was much simpler.

The fact the data was stored in Australia "was neither here nor there" as a lot of our data was already stored around the world.

There have been a "relatively small number" of healthcare workers who'd applied for accommodation to avoid infecting their families.

Bloomfield has assured New Zealand he's been sleeping, despite the unfriendly hours of the World Health Assembly, as there were Ministry who'd staffed the graveyard shift to monitor it.

Bloomfield said New Zealand goes "to do our bit" and the Kiwi diplomats had a very good reputation among their colleagues, when asked whether our response had improved our mana at the WHO.

Those putting fake contact details at sign-in pages were potentially putting others at risk, said Bloomfield.

There would be people who didn't want to download the app and the Ministry was putting an effort into promoting the app, when asked what the Ministry was doing in relation to people who couldn't afford mobile data.

Spark and Vodafone had made data free on a mental health app and Bloomfield said he was confident the Ministry had left "no stone unturned" when asked whether the same could happen with the Covid Tracer.

Ten hotels in Auckland are available for quarantine or managed self-isolation and there's also another in Christchurch if a larger number returned.

Bloomfield said "unfortunately" he wasn't part of the negotiations to get the origins of the pandemic included in the resolution as "it would have been fascinating".

He admitted it "could be confusing" with how many apps there was but what wasn't confusing, he said, was downloading the Covid Tracer app.

Users' data is kept securely on their phones, the Ministry of Health said, and is stored for 31 days and then automatically deleted.

Users can also register their details to the National Close Contact Service in order for them to be able to contact quickly if needed.

This morning Bloomfield told Newstalk ZB's Mike Hosking that privacy would not be compromised by the app and personal details were held "securely" at the Ministry.

Bloomfield said the app was complimentary to physical contact-tracing.

On the World Health Assembly resolution reached last night to review the pandemic, Bloomfield said New Zealand was also interested in other aspects of the resolution including fair access to vaccines.