A booster shot requirement for COVID-19 vaccine passes is an option Prime Minister Jacinda Ardern has "kept open".
Vaccine certificates were introduced in November last year to allow those with two doses of the Pfizer jab access to places that require proof of immunisation under the new COVID-19 Protection Framework or 'traffic light' system.
Under the new framework, which replaced the alert levels, proof of vaccination is required when entering hospitality venues, events and other close contact businesses such as hairdressers.
At the more restrictive 'orange' and 'red' levels, for example, hospitality venues that choose not to check vaccine passes must remain contactless, while those that do check for certificates are free to open and serve guests.
Vaccine passes are valid for six months and the current requirement to get one is two doses of the COVID-19 vaccine. But with the threat of the Omicron variant, the Government is keeping an open mind about adding a booster shot condition.
"Currently our vaccination passes do not have the booster set within them. It is an option we've kept open," Ardern told reporters on Monday.
"But right now the most important message for us to share is to everyone: yes, fantastic to have two doses, but for Omicron, the evidence tells us you will have greater protection with a booster. It reduces the chance of severe illness and hospitalisation."
The Omicron threat
New Zealand has so far been spared from an Omicron outbreak but Ardern said it's only a matter of time before it finds its way into the community from managed isolation and quarantine (MIQ) facilities.
An MIQ worker at the Stamford Plaza tested positive for Omicron but so far all seven of her close contacts have tested negative. Of the case's 67 contacts identified, 43 have already returned negative test results.
The Ministry of Health registered 42 new cases in MIQ on Monday, compared to 16 new community cases. More than 260 Omicron cases have been detected at the border since December.
"We know that with Omicron, it is a case of when, not if, and that is why the booster campaign is just so critical," Ardern said.
Regions with Omicron outbreaks will be moved to the more restrictive red traffic light setting, Ardern added.
"What we have already indicated is that if we have Omicron in the community, we would look to move into red settings as a way of trying to slow down the spread.
"Keep in mind, that brings in gathering limits, it uses masks, social distancing, and also has special requirements on the way that hospitality operates - people must be seated and separated for instance.
"All of those measures are all designed to try and slow down the spread of a variant like Omicron."
While research shows Omicron is less severe than Delta because it does not infiltrate the lungs, the World Health Organisation (WHO) says it should not be categorised as "mild".
"Just like previous variants, Omicron is hospitalising people and it is killing people," WHO director-general Tedros Adhanom Ghebreyesus said earlier this month.
It's all too real for Australia where COVID-19 is once again spreading like wildfire. New South Wales reported 29,504 new cases on Monday and 17 deaths, while neighbouring Victoria registered 22,429 cases and six deaths.
While there is some evidence of a drop in the effectiveness of current COVID-19 vaccines against the Omicron variant, Pfizer CEO Albert Bourla said earlier this month a third dose provides "quite good protection against deaths, and decent protection against hospitalisations".
A booster dose is up to 75 percent effective at preventing symptomatic infection and 88 percent effective at preventing hospitalisation, according to data from the UK Health Security Agency. But it's unclear how long a booster dose will provide protection.
Bourla said a redesigned COVID-19 vaccine that specifically targets the Omicron variant is likely needed and his company could have one ready to launch by March.
Booster shots can now be booked online in New Zealand for those who had their second dose four months ago.
Ardern received her booster on Monday at the Tāmaki Vaccination Clinic in Auckland. She said more than half of the New Zealanders eligible for a booster have now had one.
"We're encouraging all eligible New Zealanders to please go and get your booster as soon as possible," she said.
"The traffic on the website has been good. Today, 66,000 people have made a booking, as of midday. To give you a point of comparison, my rough recollection is that in days prior it's been more like 12,000, so a good increase in uptake."
The ability to book a booster on Monday coincided with the commencement of vaccination for children aged 5-11, and the end of the requirement to be either fully vaccinated or have a negative test to leave Auckland.
"Over the summer period, we put in place additional protections to make sure that we were easing those borders as safely as we could," Ardern said.
"But you'll see that through the remarkable efforts of our public health workforce, through vaccination and restrictions, we have managed to get Delta down to extraordinarily low levels. That means the risk posed by altering that border now is very low."
It's also the day New Zealanders travelling from Australia were meant to be able to return without spending time in MIQ. But this was delayed until the end of February due to the threat of Omicron.
Ardern said she will provide an update on traffic light settings on Thursday. All regions are currently at orange, except for Northland which is at red due to its relatively low vaccination rate of 86 percent of the eligible population.
"We have the ability to learn from other nations and see the way that Omicron is behaving and prepare ourselves for that," Ardern said.
"That will mean altering some of the things we do, particularly on testing, isolation and contact tracing, and we'll look to share those plans over the coming weeks."