The existing Pfizer/BioNTech vaccine is essentially three doses, not two. Research shows that boosters are more effective against symptomatic infection with Omicron than two jabs, and better at keeping people out of hospitals with Covid.
The more people who get the extra dose here, the less likely our health system will buckle under the strain of a big Omicron wave. The fewer symptomatic cases there are, and the less severe infections there are, the better.
Current vaccines are less effective against Omicron than earlier versions of the coronavirus but boosters raise that protection level. Omicron is both faster spreading and produces far more cases than Delta, but also doesn't attack the lungs the same way.
Boosters are part of a package of reduced public mixing and more mask-wearing. People are also being urged to plan for isolation at home. Ardern also said 20 per cent of children aged 5 to 11 have had a paediatric dose or are booked for one.
The Prime Minister suggested the country had an advantage, with boosters and shots for children already underway.
But New Zealand clearly needs to drastically increase booster uptake over the next six weeks and is just calling for people to line up going to cut it?
Perhaps anyone close to the four-month eligibility mark for a third dose, should be able to get it now, rather than having to wait another one or two weeks.
The daily number of boosters administered needs to be double the 42,000 reported on Saturday. So far the number of booster shots delivered in total - 946,000 - is about three million short of where it ideally eventually should be.
Access to boosters via pharmacies, vaccine centres and medical clinics is now easier, but that may not be enough. Things that worked before, such as mobile vaccine buses targeting specific areas and walk-in mass events, could help again. The hard work Māori and Pasifika health leaders put in with their communities during the general rollout paid off and could do so again.
A report on Saturday from the United States Centres for Disease Control and Prevention on three studies said the third dose is 90 per cent effective at preventing the need for hospital-level care with the variant compared to unvaccinated people. In contrast, that dropped to 57 per cent for people whose second dose was more than six months earlier. Cases and deaths were lower among people with three doses than two, and much lower than for the unvaccinated.
And the CDC released more research that adds to evidence boosters at least halve the likelihood of Omicron symptomatic infection compared to two shots. It put the reduction at 66 per cent. A new study from Qatar also found that boosters halved the number of symptomatic infections compared to two-dose vaccinations.
The CDC is now telling people to be "up to date" on their vaccinations as a way of dealing with the messaging problem left over from when two shots were considered "fully vaccinated". Ardern echoed that language yesterday.
Boosters are essential to dealing with Omicron. As tired as New Zealanders are of the pandemic, people should make the effort to get that third jab.