New Zealand's first group of border workers have officially been vaccinated.

Director-general of Health Ashley Bloomfield says today's vaccinations of our dedicated border staff marks a significant step forward in the fight against Covid-19.

"A milestone that protects those at highest risk of getting the virus and helping to reduce the risk of spreading into the community," he said.

Yesterday, 29 vaccinators completed a week of preparation and received their first jab.

On Monday, border workers in Wellington will start to receive the vaccine, followed by those workers in Christchurch on Wednesday.

There are also no new cases of Covid-19 in the community, the Ministry of Health reported today. Seven cases in total are so far connected to the mystery outbreak first uncovered on Valentine's Day, but officials said there has been no known further transmission of cases related to the cluster.

It will take a few weeks to vaccinate all 12,000 border and MIQ workers, before their household contacts.

Bloomfield said we need to remember that this pandemic is the most significant global public health challenge in a century and management it will require all our efforts for some time to come.

"Even though vaccinations have begun, it's important everyone stays vigilant and sticks to the basics: staying home if unwell and getting advice about having a test, washing hands and coughing and sneezing into the elbow, and wearing masks or face coverings on all public transport. "

Dr Nikki Turner, director of the Imunisation Advisory Centre, said people keep asking her how safe the vaccine was and she wanted to ensure the public it was incredibly safe.

She said she'd been told the vaccine came to early but the clinical trials shows it's an incredibly effective vaccine.

"We do know it can cause allergic reactions and we are ready for that.

"It can give you sore arm or achy but we are ready and expecting that.

"We are confident about the safety of this vaccine ... there is nothing to worry about with this vaccine," Turner said. "We have not rushed the authorisation process."

Healthcare, essential workers and those most at risk will have their vaccinations in the second quarter of the year.

The remaining general public vaccinations are expected to begin in the second half of 2021.

The Pfizer vaccine requires two jabs about three weeks apart in order to be effective.

Frontline workers vaccinations will mostly take place in their usual workplace such as MIQ facilities.

Dr Nikki Turner, director of the Immunisation Advisory Centre, said it is likely the general public would need to visit a specific vaccination site or clinic, which each DHB was working to set up in its region.

The Herald understands people will need to book an appointment before turning up but the details of that are still to be ironed out.

New Zealand has pre-purchased four vaccines, from firms Pfizer and BioNTech; Janssen Pharmaceutica; Novavax; and AstraZeneca.

The first agreement was for 1.5 million doses from Pfizer and BioNTech.

This is enough vaccines for 750,000 people, with each person needing two doses about a month apart.

An in-principle agreement has been signed with Janssen Pharmaceutica to purchase up to five million vaccines - likely to be a single dose.

In December, the Government signed a further agreement with Novavax to purchase 10.72 million doses of its vaccines - enough for two doses for 5.36 million people - but this isn't expected until later this year.

The other deal signed in December would secure New Zealand 7.6 million doses of the Oxford-AstraZeneca vaccine - enough for 3.8 million people.

Companies who make the vaccines say they are between 90 to 95 per cent effective.

Bloomfield has said that level of effectiveness not only protected people from severe illness or death but also symptomatic illness.

"The ongoing trials and the ongoing monitoring of people who have been vaccinated will give us an idea of how long the immunity might last but all the studies that are being done suggest that especially once people get that second dose they do have a good response and immunity does last for at least some months."