The Government will reveal next week who will be eligible for a second booster shot. Photo / Bevan Conley
ANALYSIS:
The key question for the rollout of a fourth dose of the vaccine for protection against Covid-19 is whether it will reflect the greater risk of severe illness for Māori and Pasifika.
The immunocompromised, elderly and those in disability of aged-care facilities are all at greater risk from Covid-19.
It's already been signalled that they will be able to have a second booster shot for winter, starting in July for most of the eligible people. What hasn't been signalled is whether younger Māori and Pasifika will also be eligible.
The Government was faced with a similar question when the vaccine rollout started last year.
Its expert immunisation advisory group recommended a number of groups to be closer to the front of the queue, including all people aged 65 and over and Māori and Pasifika aged 50 and over.
The Government rejected that advice, meaning 160,000-odd Māori and Pasifika aged between 50 to 64 were not eligible in accordance with what the science showed.
Instead, the Government provided 40,000 vaccine doses to Māori and Pasifika health providers to lead a whanau-based approach - which the expert group had recommended alongside prioritising younger Māori and Pasifika.
The rejection prompted top Māori GP Rawiri Jansen to quit the group.
For the second booster decision, the Government will be mindful of the latest research, but with the Labour Party sliding in the polls, it may also be wary of what the median swing voter might think.
What the science says
The experts' recommendation was based on data showing much higher rates of infection among Māori and Pasifika in the August 2020 outbreak: six per 100,000 for Māori and 32.3 per 100,000 for Pacific peoples, compared to 1.3 per 100,000 for European/other.
A study in the NZ Medical Journal, looking at all of the cases up to and including the August 2020 outbreak, found that a 44-year-old Māori person had the same hospitalisation risk as a 40-year-old Pacific person and a 65-year-old New Zealand European person.
Furthermore, Māori are two-and-a-half times and Pasifika three times more likely to need hospital care for Covid-19 than non-Māori, non-Pacific people, according to modelling by Te Punaha Matatini researchers that controlled for age and pre-existing conditions.
Similar research overseas led to Canada and Australia allowing younger indigenous peoples be eligible for the vaccine earlier; Australia's winter booster programme, for example, is open to all those aged 65 and over, and 50 and over for indigenous people.
What the NZ data shows
Epidemiologist Professor Michael Baker said the Ministry of Health should have the best available case and hospitalisation data to show who is most at risk, and therefore who should be eligible.
"Without looking at the data in detail, I think it would be important to offer boosters to Māori and Pacific people at a younger age, just as we are now doing for funded influenza vaccination."
Ministry data on its website doesn't include hospitalisations by age and ethnicity, but such data is available for Covid deaths.
For the 504 deaths where Covid-19 is officially the cause, 74 (14.7 per cent) were Māori, who make up about 17 per cent of the whole population.
But this doesn't account for the different age profiles for each ethnicity.
Statistics NZ population projections for June 2022 show that Māori make up 20 per cent of the 0-59 age group; they make up more than twice the proportion - 41 per cent - of Covid-caused deaths in the same age bracket.
Māori are 11 per cent of the 60-69 age group but 35 per cent of the deaths, 7 per cent of the 70-79 age group but 15 per cent of the deaths, 5 per cent of the 80 to 89 age group but 7 per cent of the deaths, and 3 per cent of the 90-plus age group but 4 per cent of the deaths.
Ministry data suggests the virus has hit Pasifika even harder than Māori.
Pasifika are 10 per cent of the under-60 population but 20.5 per cent of the deaths, 4.4 per cent of the 60-69 population but 29 per cent of the deaths, 3.1 per cent of the 70-79 population but 9 per cent of the deaths, 2.3 per cent of the 80-89 population but 12 per cent of the deaths, and 1.6 per cent of the 90-plus population but 7 per cent of the deaths.
Contrast this with the data for European/Other, who make up two-thirds of the 0-59 age group and 28 per cent of the deaths, 77.5 per cent of the 60-69 age group and 31 per cent of the deaths, 84 per cent of the 70-79 age group and 66 per cent of the deaths, 88 per cent of the 80-89 age group and 77 per cent of the deaths, and 93.1 per cent of the 90-plus age group and 84 per cent of the deaths.
This data must be viewed with caution as it doesn't account for several relevant variables including vaccination status and access to the vaccine, access to healthcare, pre-existing conditions or people's living conditions.
What the experts say about a second booster
Jansen, who is also a co-leader of the National Māori Pandemic Group Te Rōpū Whakakaupapa Urutā, hopes the Government will change its mind for the second booster shot.
As well as Māori and Pasifika aged 50 and over, he repeated the other recommendations for vaccine priority to include every prisoner, homeless person and person with drug and alcohol addiction issues.
Vaccinologist and Auckland University Associate Professor Helen Petousis-Harris argued for an age of 45 for Māori and Pasifika, given evidence that suggests a "consistent 20-year gap for infectious diseases including Covid".
She added: "Recommending it is one thing, but having it actually available and accessible to these groups is another."
A University of Waikato study last year found that poorer neighbourhoods and those with higher proportions of Māori and people over 65 years old had less vaccine access than communities that were wealthier, whiter and younger.
It also found that neighbourhoods with a high proportion of Pacific residents had, on average, slightly better access to vaccine services than areas with a low proportion of Pacific residents.
The Government is unlikely to allow anyone wanting a fourth dose to just walk into a clinic and be able to get it - though it is constantly reviewing the science on waning immunity.
Immunisation Advisory Centre director Professor Nikki Turner, who is on Covid-19 advisory groups to the Government, said the vaccine was still effective against severe disease six months after a first booster dose.
"However, there are signs of waning immunity, particularly for those who are older and more immunocompromised," she said.
She pointed to USA data showing vaccine effectiveness against hospitalisation for three doses - for adults 50 and over - was 93 per cent at 14 to 59 days after the most recent shot. It fell slightly to 84 per cent at six to eight months after the last dose, but to just 50 per cent for the immunocompromised.
She also noted data from Israel, where a second booster for those aged 60 and over reduced the risk of severe infection by a factor of 4.3, and the risk of confirmed infection by a factor of 2. This was compared to those who hadn't had four doses.
"Those who received a second booster had a 78 per cent lower mortality rate from disease than those who only received one booster," she added.
The details of who will be eligible for a fourth dose are expected next week.