The Government aspires to have everyone who wants a Covid-19 vaccination receiving it by the end of the year. Photo / AP
Last year was New Zealand's "year of elimination" - and now 2021 is set to be the year of the vaccine. Science reporter Jamie Morton answers some of the key questions.
When are the vaccines arriving and who's first in line?
Border and high-risk workers, along with their contacts like family, are set to be vaccinated in March or April, and the general public from around the middle of the year.
While those front-line personnel most exposed to Covid-19 are first in line, those next to receive it will be otherwise high-risk health, public sector and emergency services workers.
The next group will be people in the community - especially older people and those with underlying conditions.
New Zealand has pre-purchased four vaccines, from Pfizer and BioNTech; Janssen Pharmaceutica; Novavax; and AstraZeneca.
The first purchase agreement was for 1.5 million vaccines from Pfizer and BioNTech.
This is enough vaccines for 750,000 people and each person will need two doses of this vaccination, about a month apart.
An in-principle agreement has been signed with Janssen Pharmaceutica to purchase up to 5 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.
How do they work?
Differently.
The flu shots we typically get each year are "inactivated" vaccines - or those that don't contain any live viruses.
Instead, a virus that has been rendered inactive by special treatment is introduced into the body, allowing the immune system to learn from its antigens how to fight live versions of it in the future.
The Oxford-AstraZeneca "viral vector" vaccine works slightly differently, by using a virus that has been genetically engineered so that it can't cause disease - but carries the instructions for our body to produce coronavirus proteins to safely generate an immune response.
The Novovax vaccine is a "protein" vaccine and uses only harmless fragments of the virus shells that mimic the Covid-19 virus, to safely generate an immune response.
These teach our cells how to make a protein, or even just a piece of a protein, that triggers an immune response inside our body.
That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our body.
Covid-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the "spike protein", which is found on the surface of the virus that causes Covid-19.
The Janssen vaccine, meanwhile, is a "recombinant vector vaccine" that uses a human adenovirus to express the virus spike protein in cells.
How do we know they're safe?
None of these vaccines use the live virus that causes Covid-19 - and they don't change or interact with our DNA in any way.
They also must comply with international standards and local requirements for quality, safety and efficacy before they can be approved by Medsafe and used in New Zealand.
Although Medsafe is streamlining its assessment processes and prioritising the evaluation of the vaccines over other medicines, they'll still have the same rigorous level of scrutiny that all medicines undergo.
New Zealand's place near the back of the global queue - largely because of our successful response wiping out local transmission - means regulators have more time to assess.
What's the story with the European Union's position?
Tighter controls just introduced by the EU on vaccines headed for outside countries - including New Zealand and Australia - could slow down shipments.
The clampdown - giving EU countries powers to halt vaccine exports if companies hadn't first honoured their contracts with those nations - came amid worries inside the bloc that doses it had secured could be diverted elsewhere.
While the Ministry of Health has responded with concern over the new rules, which apply to the Pfizer and AstraZeneca vaccines, it still expects vaccine manufacturers to stick to timeframes in purchase agreements.
Will they cost people money?
No - they'll be delivered free. They also won't be mandatory.
So how many people is the Government hoping to vaccinate?
Ideally - at least 90 per cent of the population.
Director-general of health Dr Ashley Bloomfield has said 70 per cent vaccination would be the minimum needed for herd immunity, depending on factors including vaccine efficacy.
But polling has suggested only about 70 per cent of New Zealanders would be prepared to get vaccinated, and a further 20 per cent - the "vaccine hesitant" - would get a jab if they were very sure it was safe.
About 10 per cent said they wouldn't.
Alongside its roll-out, we can expect a large-scale public education and awareness campaign from the Government to ensure people are reliably informed.
The Government is planning for an extra 2000 to 3000 fulltime vaccinators who will be trained and available when needed throughout New Zealand.
This workforce will continue to scale up during 2021 in line with vaccine delivery schedules.
The Ministry has also contracted the Immunisation Advisory Centre to provide training on Covid-19 vaccines, which is expected to start this month, initially for those vaccinators who will deliver the Pfizer vaccine and then for nurses, doctors and pharmacists.
What happens if New Zealand has another nationwide outbreak?
In this case, planning allows the roll-out to prioritise vulnerable groups like aged care residents, Māori and Pacific people, then others aged over 65 years.
Others include people under 65 with underlying conditions, and those living in long-term residential care settings.
What will this mean for the rest of New Zealand's immunisation programme?
That's unclear.
But one expert says the roll-out could be a "double-edged sword" for New Zealand's wider immunisation rates, with the potential to help or hinder them.
Vaccination programmes such as the childhood immunisation schedule, HPV and seasonal flu shots have delivered increasingly good coverage over recent times, but have failed to hit set targets.
Immunisation Advisory Centre director Dr Nikki Turner said this year's effort could potentially lift these rates further by addressing long-standing access problems and fostering more public trust.