Protecting hapu māmā and newborn babies through immunisation during pregnancy in Aotearoa New Zealand

Maternal vaccination protects māmā during pregnancy and are the first immunisation event for pēpi, protecting them during the first months of life when they are vulnerable to infection but not yet old enough to be immunised themselves.¹  This briefing outlines how we are performing in equitable maternal immunisation coverage in Aotearoa New Zealand (NZ) within the context of childhood immunisation targets, and reviews opportunities for raising immunisation coverage in this key group. 

Why is maternal immunisation important?

In NZ, deaths from pertussis occur almost exclusively in unimmunised infants.² Among infants who require intensive care, permanent brain or lung damage is common.² In 2023, 20 infants under 5 months old were hospitalised with pertussis, most of which were Māori or Pacific pēpi³. Three of these infants died⁴. 

The risk of complications from influenza infection in pregnancy is substantial for hapū māmā^{2; 5}. Influenza in pregnancy increases the likelihood of preterm birth and low birth weight⁶ and may also be associated with an increased risk of maternal⁶, fetal, and neonatal death.⁵

Covid-19 vaccination is also recommended and funded for all hapū māmā in New Zealand, but is not included in this study.¹

Maternal immunisation coverage: current evidence

Maternal immunisation coverage in NZ is below 50% and Māori and Pacific people are significantly less likely to be immunised than other groups.⁷ Those from areas of high deprivation are also less likely to be immunised, with Māori and Pacific māmā living in these areas at greatest disadvantage. These findings reflect stark inequities in access to maternal health care and signal the need for system change. 

Geospatial analyses from 2013 to 2020 found the low overall maternal immunisation coverage meant that more than 90,000 women and their babies were not protected.⁸ Significant regional variation in maternal immunisation coverage for influenza and pertussis was also concerning.⁸ Areas such as Canterbury, Auckland and Capital & Coast have relatively high levels of immunisation coverage compared to Tairāwhiti, Waikato, Northland, Bay of Plenty, West Coast and Taranaki (Figure 1). These findings are available in our interactive app (Figure 2) at: https://geohealthlab.shinyapps.io/hapumama/ and a summary of immunisation coverage from 2013–2020 can be found in the Appendix below. Many areas with low maternal immunisation rates also have persistently low childhood immunisation coverage.⁹ However, there are further intra-regional variations as declining and stagnating coverage can be found even in more affluent areas.¹⁰ 

Figure 1. Overall level of maternal immunisation coverage for Influenza and Pertussis from 2013 to 2020 by District Health Board.

Figure 2.  A screenshot of the interactive app Shiny app example (condition, by year).

Unlocking opportunities for equitable improvements

Many factors contribute to poor and inequitable immunisation uptake including accessibility of maternal healthcare¹¹, transport and childcare costs, and time constraints.¹² Outstanding bills at general practices can prevent some māmā from seeking free immunisations¹³ or they may assume there will be an associated charge.¹⁴ Lack of awareness about disease severity and the availability and importance of maternal immunisation¹⁵, particularly among Māori and Pacific whānau (extended families)¹⁶, and a mistrust of the health system also contribute.¹⁷ 

Recent challenges with the Covid-19 immunisation rollout resulted in the spread of misinformation, mistrust and vaccine hesitancy which has extended to childhood and maternal immunisations.¹⁸ Innovations in service delivery to improve coverage of the Covid-19 immunisation drive proved effective in the pandemic response, but these have largely not been carried over into the other funded immunisations in NZ.¹⁹ 

The government proposes immunisation targets and incentives for general practice to improve immunisation coverage so that 95% of tamariki are fully immunised at 24 months of age. It is not clear whether these targets will improve maternal immunisation as having targets only for childhood immunisation could divert attention away from immunising hapū māmā. Hapū māmā who are immunised may be more likely to vaccinate their pēpi²⁰, so including hapū māmā in targets could be beneficial. 

Health targets have previously improved childhood immunisation coverage and significantly reduced inequities for Māori and Pacific.²¹ These targets were effective because the previous District Health Boards (DHBs) were accountable for meeting them and for coordinating the health services within their region.²² However, if accountability for the new proposed targets is with general practice, this will put pressure on primary care and risk inadequate resources for an already stretched sector.  Accountability at general practice level may also worsen outcomes for whānau who need additional support with immunisation, as they may have difficulty enrolling with a practice which is focused on reaching targets.²³

A multifaceted approach is needed to improve immunisation uptake nationally. Our research team is collaborating with the healthcare sector in an HRC-funded project to co-design interventions with iwi healthcare providers to improve maternal immunisation coverage. We are taking a multisystem approach, developing tools and resources to support health systems to work effectively, healthcare providers provide services, and individuals to be vaccinated. If we can demonstrate success, our ambition is for the resources and tools developed during this project to be implemented across NZ to improve immunisation coverage and health outcomes for whānau. 

Author details 

Dr Amber Young, He Rau Kawakawa | School of Pharmacy, Te Whare Wānanga o Ōtākou | University of Otago, Ōtepoti | Dunedin

Dr Matthew Hobbs, Faculty of Health | Te Kaupeka Oranga, and GeoHealth Laboratory | Te Taiwhenua o te Hauora, University of Canterbury | Te Whare Wānanga o Waitaha, Christchurch | Otautahi, New Zealand | Aotearoa.

Associate Professor Esther Willing, Kōhatu - Centre for Hauora Māori | Division of Health Sciences | Te Whare Wānanga o Ōtākou, University of Otago| Ōtepoti | Dunedin, New Zealand | Aotearoa

Dr Gabrielle McDonald, Kōhatu - Centre for Hauora Māori | Division of Health Sciences | Te Whare Wānanga o Ōtākou, University of Otago| Ōtepoti | Dunedin, New Zealand | Aotearoa

Dr Pauline Dawson, Women’s And Children’s Health | Te Tari Hauora Wāhine me te Tamariki, Dunedin School of Medicine | Te Kura Whaiora o Ōtepoti, University of Otago | Te Whare Wānanga o Ōtākou, Ōtepoti | Dunedin

Dr Lukas Marek, GeoHealth Laboratory | Te Taiwhenua o te Hauora, University of Canterbury | Te Whare Wānanga o Waitaha, Christchurch | Otautahi, New Zealand | Aotearoa

Dr Louise Fangupo, He Rau Kawakawa | School of Pharmacy, Te Whare Wānanga o Ōtākou | University of Otago, Ōtepoti | Dunedin

Professor Peter McIntyre, Women’s And Children’s Health | Te Tari Hauora Wāhine me te Tamariki, Dunedin School of Medicine | Te Kura Whaiora o Ōtepoti, University of Otago | Te Whare Wānanga o Ōtākou, Ōtepoti | Dunedin

Updated 31 May 2024: An earlier version of this article noted that four infants died from pertussis in 2023, when it was actually three infants (in the last whooping cough epidemic in 2018, there were four deaths).

Appendix 1 – A summary of influenza and pertussis coverage in pregnancy 2013-2020