A key focus of the health-related sustainable development goal (SDG) 3 is universal
health coverage (UHC), including access to safe, effective, quality, and affordable
essential medicines and vaccines. However, the challenges to achieving UHC are substantial,
especially with increased demands on the health sector and with most budgets being
static or shrinking.
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Immunization programmes have been successful in reaching children worldwide. For example,
86% of the world’s infants had received three doses of diphtheria-tetanus-pertussis
(DTP3) vaccine in 2018.
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The experiences from such programmes can contribute to UHC, and as these programmes
strive to adapt to new global strategic frameworks, such as Gavi, the Vaccine Alliance’s
strategy Gavi 5.0 and the World Health Organization’s (WHO) Immunization Agenda 2030,
these efforts can inform the progressive realization of UHC. Immunization programmes
that can sustain regular levels of contact between health providers and beneficiaries
at the community level have enabled new vaccines to be added to routine immunization
schedules and other interventions to be delivered to children and their families.
In addition, experiences from both polio campaigns and the child health days strategy
show that incorporating additional interventions into campaigns can increase coverage
of these interventions as well as of vaccinations.
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Improving immunization coverage
Considering how to expand integration efforts and to better focus immunization on
the most disadvantaged, including attention to addressing social determinants of health,
will be critical for further progress. The Equity Reference Group for Immunization
has conducted analyses based on published and unpublished literature, as well as a
series of interviews with experts working at global, national and community levels
to highlight several related challenges and opportunities. Here we discuss challenges
and opportunities related to data quality, vertical immunization programmes, underserved
children and gender.
In 2018, 19.4 million children younger than one year of age did not receive DTP3,
and approximately 41% of these children live in countries that are polio-endemic,
fragile or affected by conflict.
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In addition, a growing share of children live in middle-income countries where vulnerability
and social exclusion, particularly among the urban poor, prevents many from receiving
vaccination. Children living in remote rural areas, although long identified as a
target population for immunization programmes, continue to be underserved. Furthermore,
immunization programmes often ignore inequities caused by bias and discrimination
in response to the social constructs of ethnicity and gender.
Data quality
There is growing evidence on the reasons these inequities in immunization exist and
how to address them. Acting on this evidence is the challenge to increasing coverage,
particularly as it will require redistributing resources, prioritizing those who are
often subject to discrimination and operating in challenging contexts. Currently,
opportunities that are important considerations for immunization decision-makers and
implementers exist.
The first opportunity is the improvement of data quality and use of both traditional
surveys and new technologies. Approaches such as linking data sets and use of electronic
health information systems can facilitate recording and reporting of real-time data.
Simple analyses using existing data can also help us better understand key equity
issues within countries. For example, in 2018, WHO released an equity analysis of
ten countries that Gavi has identified as the highest priority for childhood immunization.
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Using Demographic and Health Surveys (DHS), the report presents disaggregated data
on, and associations with, DTP3 coverage by key characteristics of children, mothers
and households. This type of information can serve as a basis for more detailed explorations
at both national and subnational levels, and as a baseline for future efforts to redress
equity gaps. New technologies can provide a better user interface and geospatial information
gathering, particularly to improve traditional survey methods and tools. Such advances
would facilitate new opportunities that big data and artificial intelligence approaches
are bringing to public health.
The second opportunity is innovations such as machine learning and use of satellite
imagery, which are already improving estimates of how many children live in different
geographic areas, and supporting better visualization of data, which health workers
can act upon. Polio eradication programming, for example, has shown how the use of
granular data through geographic information systems mapping, coupled with surveillance
data, can identify children who are hard to reach by the health-care system. Predictive
models informed by data across sectors, such as health, protection, transport and
telecommunications, could identify pockets of low coverage even where surveys have
not been conducted. However, as quality data are only relevant if used at local levels
for planning and budgeting, capacity must be built at national and sub-national levels
to better use these data to adapt and expand service delivery strategies. These transformative
investments will be critical for both immunization programming and UHC, even as discussions
of how best to measure UHC continue.
Vertical programmes
The vertical nature of immunization programmes is a challenge. This organizational
structure has enabled robust vaccination gains, but has been implemented without enough
attention to how immunization assets can be used more broadly. Identifying the right
mix of interventions to integrate with immunization services, informed by cost–benefit
and cost–effectiveness analyses, is critical to ensure that integration does not overburden
health workers or negatively impact coverage and quality.
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At the global level, additional research is needed to further develop an evidence
base around new service delivery models and innovations to simplify vaccine delivery
for all children, particularly those living in difficult-to-reach areas. Experts point
to the success of strategies that use meticulous microplanning to identify the unreached,
engage communities and improve reach through public-private partnerships. Indeed,
one of the core axes of UHC is that communities own and drive the design and implementation
of services. Immunization programmes are well placed to support this, building on
the strengths of the WHO’s Reaching Every District approach, which includes community
engagement as a cornerstone. In addition, needle-free vaccine administration and thermo-stable
vaccines are promising innovations to enable the health system to simplify and expand
delivery to marginalized children. Adoption of novel strategies, such as optimizing
delivery strategies and doses per container, reduced dosages and adapted target age
ranges within campaigns may reduce disease burden in displaced and intermittently
accessible populations. Furthermore, the rollout of human papillomavirus (HPV) vaccination
in many countries presents new opportunities for reaching adolescents with other services,
such as screening programmes and treatment or other vaccines, and provision of information
and life skills. This increased reach can facilitate access for adolescents and can
reduce costs and burdens related to delivering interventions separately.
Underserved children
Developing better approaches for children who may be accessible geographically, but
who remain underserved is also a challenge. In some cases, children are underserved
by commission, that is, their families deliberately avoid vaccination, while others
by omission due to a variety of service delivery and social factors leading to intentional
or unintentional exclusion. Incorporating the latest thinking around effective behaviour
change approaches into programme and communication strategies may provide new opportunities
to reach these children. Reaching these children will also require health systems
strengthening, improved quality of care, intersectoral and intragovernmental collaboration,
and new emphasis on social justice, non-discrimination, civil society engagement and
accountability, among other efforts.
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Gender
A final challenge is to ensure that gender is recognized as a critical, cross-cutting,
and influencing factor, and ensuring that gender analyses of immunization are not
restricted to comparing coverage outcomes between boys and girls. Studies show that
maternal education and maternal age are key determinants of whether a child is immunized.
As well, the agency and empowerment of women, and women’s access to quality services
can affect the likelihood of childhood immunization.
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We must identify and test ways in which immunization programmes can mitigate gender-related
barriers without undermining, but rather ideally contributing to, women’s empowerment
in different settings. HPV vaccination raises additional gender and equity considerations,
particularly as services for adolescents can be quite limited in both availability
and quality in many settings.
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Addressing inequities
The strategic importance, effectiveness and cost–effectiveness of focusing on the
poorest and hardest-to-reach children has been emphasized before.
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Equity in immunization may also contribute to building solidarity within countries
for UHC, as everyone, across all socioeconomic levels and from a variety of backgrounds,
will benefit from increased herd immunity. However, building solidarity for social
and health programmes can be a key challenge in settings where the more advantaged
people question why they should pay taxes to ensure services for the less advantaged.
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Fortunately, immunization programmes are an example of a public good which, when strengthened
and expanded, will benefit those same tax-payers, while also benefitting those who
have been previously denied this essential intervention. The financial return on investment
in vaccines has been found to be up to 44 times their cost.
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We must address inequities in immunization not just for the obvious health, financial
and political benefits that come from herd immunity and absence of disease, but because
without greater achievement in immunization among children living in urban poor, remote
rural or conflict settings, it will be impossible to collectively reach our shared
goals for primary health care and UHC.
We have highlighted some of the innovations in the field, as well as the existing
assets that immunization programmes can bring. However, using the full potential of
immunization programmes to advance UHC will require strategic changes, such as increased
efforts to integrate with other services and reaching children never reached by the
health system.