NEW Zealand began easing into a less restrictive lockdown today with 400,000 people returning to work and 75% of the economy operating again after weeks of stay-at-home measures.

The nation saw its final day of strict level-four lockdown restrictions yesterday, and today eased into the level-three measures – which allow New Zealanders to hold small funerals and buy takeaways, and let more people return to work.

The country has reported 19 deaths and 1472 confirmed and probably cases, of which 1214 have covered.

This morning Prime Minister Jacinda Ardern encouraged the public to stay vigilant against the virus during the new phase, and took aim at countries who are operating or have considered a "herd immunity" strategy, saying she "simply would not have tolerated" the number of deaths it would have resulted in.

"Herd immunity" is aimed at getting a large number of people to contract the virus and therefore develop antibodies to it, limiting the risk of it spreading among the community. However little is known about the level of immunity gained after catching Covid-19, if any, and the strategy would involve a large number deaths.

By not implementing lockdown measures Sweden is currently following this strategy and has registered 18,926 coronavirus cases and 2274 deaths in a population of 10.3 million people.

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In March chief scientific adviser Patrick Vallance said the UK would need about 60% of people to be infected to gain herd immunity and reduce transmission, but ministers have consistently denied this was ever part of their coronavirus response.

New Zealand's success in limiting the spread of the virus has been put down mainly to a swift and wide testing programme, as well as some of the toughest border restrictions in the world – initially anyone entering New Zealand would need to self-isolate for a fortnight, then days later on March 19 foreigners were banned from entering altogether.

Referring to New Zealand’s strict border controls, Ardern said: “This I think will be the case for the whole world, where they’ll be managing their borders – because unless you have herd immunity which roughly means 95% of your population either having been vaccinated or having had the disease, then that will mean most of us will be working in a situation of having to manage our borders until we have a vaccination.”

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The reporter replied: “And we can’t do the former because the vaccine doesn’t exist and we daren’t even dream of the latter because if 95% of us have had it then we’ve lost tens of thousands of New Zealand lives potentially …”

Ardern responded: “And this is the point actually – there were some countries who initially talked about herd immunity as a strategy. In New Zealand we never ever considered that as a possibility ever. Herd immunity would have meant tens of thousands of New Zealanders dying and I simply would not tolerate that and I don’t think any New Zealander would.”

Currently the UK is operating an open-borders policy with more than 15,000 passengers arriving daily. Passengers are also not tested for coronavirus on arrival.

However from next month the UK will insist passengers entering must go into 14-day quarantine.