The number of fully vaccinated district health board staff nationally has risen by 10 per cent in the last month, but up to a fifth of some DHBs' staff are not vaccinated at all.
Of the roughly 80,000-strong DHB workforce, about 85 per cent are fully vaccinated, with another 5 per cent having received one dose as at October 11 - meaning about 90 per cent of DHB clinical and non-clinical staff were partially or fully protected with the vaccine.
That compares to about 75 per cent of DHB staff across the country who were fully vaccinated when the NZ Herald analysed staff vaccination data from early September.
However, up to 20 per cent of staff at some DHBs hadn't received their first or second jab, leaving a significant hole in the country's Covid-19 defences.
Taranaki DHB had the lowest full vaccination levels at 72 per cent - just 2 per cent higher than a month ago.
It has a further 8 per cent of staff who have received one jab, leaving 20 per cent unvaccinated.
Concerningly, this was the same proportion of Taranaki DHB staff members who were unvaccinated in early September - suggesting no unvaccinated staffers had received a jab in four weeks.
A Taranaki DHB spokeswoman said it was likely some unvaccinated staff had received their vaccinations in the last month, but it hadn't yet been recorded by the DHB.
In the Wairarapa, 80 per cent of staff had received both jabs. No first dose data was provided for Wairarapa DHB.
For Bay of Plenty DHB, which covered some of New Zealand's most unvaccinated communities, 19 per cent of staff were not vaccinated with 78 per cent having had both vaccinations.
Eighteen per cent of Whanganui DHB staff hadn't had any jab. A total of 80 per cent of staff were fully vaccinated.
In Auckland - the centre of the current Delta outbreak - all three DHBs had full vaccination levels between 92-94 per cent and first dose levels between 95 and 98 per cent.
In the Waikato, where two unlinked positive cases were found on Wednesday, 86 per cent of DHB staff had had both jabs, with a further 8 per cent with one jab - identical to Tairāwhiti, another area with vulnerable communities to the virus.
In Northland, still under alert level 3, only 80 per cent of DHB staff had been fully vaccinated. However, it was nearing 90 per cent on first dose levels (89 per cent).
The data included staff who were "known to be vaccinated", meaning there could be some staff who had been vaccinated, but had not been included in this data collection.
DHB spokesperson Rosemary Clements was pleased with the overall high vaccination levels and strongly encouraged all unvaccinated staff to get their jabs.
Covid-19 vaccination hadn't been mandatory for DHB staff, unless they were in a role where they were likely to encounter the virus.
Under the recently announced vaccination mandate for healthcare workers, all high-risk workers in the health and disability sector have to be fully vaccinated by December 1 and must have had their first dose by October 30.