Generating Advocacy for Life-Course Immunization around the World

This year marked the ninth annual National Immunization Awareness Month (NIAM) in the United States. Although first recognized in 2013 by the National Public Health Information Coalition (NPHIC) to encourage parents to vaccinate their children, NIAM is now promoted by the US Centers for Disease Control and Prevention (CDC) to educate the public on the importance of staying up to date on all recommended vaccines at every stage of life.

The ’life-course’ approach to immunization addresses the need for immunization schedules and access to vaccines that respond to people’s health needs over time. This approach accounts for an individual’s stage in life, their lifestyle, and the specific vulnerabilities to infectious disease that they may face at any point. While routine immunizations are highly promoted during childhood, several immunizations – including boosters – are recommended throughout one’s life. The COVID-19 pandemic and the global rollout of COVID-19 vaccines highlight the importance of promotion of and investment in life-course immunization.

Globally, the pandemic has induced the largest decline in childhood routine immunizations in 30 years. For example, global coverage for key immunizations such as Meningitis A and Rotaviruses dropped from 86% in 2019 to 81% in 2021. This backsliding is having serious global health implications, allowing long-controlled viruses like polio to reemerge. Even in 2022, the message of NIAM remains important to amplify, for all ages.

What does it mean to vaccinate over the life course?

Life-course is not just about immunizing adults. Instead, the concept considers changing health needs over time that may be related to life stages and events, societal changes, and local epidemiology. While children are given several vaccinations meant to protect them throughout their lives, some vaccines require additional doses (“boosters”) to maintain their durability. A life-course immunization strategy can also help curtail long-standing vaccine-preventable morbidity in communities, target vaccination towards ages and other sub-populations most vulnerable, and contribute to efforts to prepare for the next pandemic.

For example, immunizations against tetanus, diphtheria, and pertussis (Tdap) are administered in infancy and childhood, and the Centers for Disease Control and Prevention recommends boosters for adults every ten years in the United States. This is the case for many other countries including Greece, Latvia, Tanzania, and Indonesia. The booster recommendation exemplifies a life-course approach to fluctuating herd immunity across age groups as well as different stages of life, since pregnant women and other caregivers are advised to receive Tdap immunizations to protect newborn health.

Furthermore, as vaccine-preventable morbidity becomes more prevalent, life-course approaches to vaccination present the opportunity to improve the long-term quality of both individual and public health. Before the introduction of a routine immunization program in the region, up to 85% of meningitis epidemics in the African meningitis belt were attributable to meningococcus serogroup A. Mass vaccination campaigns targeted those 1-29 years of age in the region, which have decreased the resurgence of these epidemics by more than 99% as of 2017.

A life-course approach to vaccination can also be used as a tool to address behavioral risks to vaccine-preventable disease that occur at varying ages. Most countries target the vaccination series against human papillomavirus (HPV), a sexually transmitted disease, to adolescents and young adults in an effort to preempt sexual debut, while some others like Armenia recommend it from 15 and 45 years of age.

Equity in Life-Course Immunization Programs

The COVID-19 vaccine rollout has thrown into stark relief, the inequities in present life-course immunization programs across the world. Vaccine equity, according to WHO, means that vaccines should be allocated across all countries based on needs, regardless of their economic status. For COVID-19 vaccines, 23% of people in low-income countries have received at least one dose compared to close to 80% of people in high-income countries.

To be clear, this is not an issue of equality whereby the concern would be whether there are enough vaccines for every country. Equity instead concerns the distribution of vaccines to those who still face barriers despite equal availability. The concept of vaccine equity gained popularity as a social media hashtag (#VaccineEquity) in 2021 urging key stakeholders to display fairness in the rollout of COVID-19 vaccinations. The gaps on global vaccine dashboards display the disparities between the fully vaccinated and boosted populations in rich countries and the under-vaccinated populations in less rich countries. In most high-income countries, booster and child vaccinations are available, yet low- and middle-income countries, particularly those in sub-Saharan Africa, Latin America, Eastern Europe, and southern Asia, still struggle to guarantee this form of protection for their most at-risk populations. In September 2021, low-income countries had only administered 1.5 doses for every 100 people whereas high-income countries had administered 100 doses for every 100 people. That is a deep divide.

The pandemic has only magnified the pre-existing inequitable trends in the distribution of vaccines, medicines, and other health-related technologies that have produced the current inequities in the allocation of vaccines.

Inequity in vaccine access continues to reduce and altogether inhibit any efforts to generate acceptance and demand particularly in low-and middle-income countries. This in turn contributes to greater disparities within and between countries while jeopardizing other global health priorities. Despite global initiatives to address underlying inequities of gender, race-ethnicity, age, and geography, sustained vaccine accessibility will require further research and political will. Acknowledging these circumstances presents a rewarding opportunity to redirect advocacy in immunization efforts across the life-course to an equitable lens.

Moving Forward

NIAM and other ongoing immunization efforts remain important to prevent barriers to global health like those outlined above. When it comes to improving healthcare access to something like immunization, messaging must be crafted in a way that both advocates and informs. Advocacy efforts should also embrace the life-course approach through equity in vaccine access and health system strengthening.

Promoting policies that support immunization across the life-course, rather than restricting it to childhood, has the potential to:

• benefit individual and population health
• promote healthy aging
• support the long-term sustainability of health systems through reduced healthcare costs
• lead to wider economic benefits by promoting workforce productivity
• support equity and universal access to primary care by providing a platform around which these services can be provided
• reduce the spread of antimicrobial resistance

Sabin’s Vaccine Acceptance & Demand (VAD) initiative partners with organizations around the world to better understand the social and behavioral drivers of vaccine acceptance and demand. As part of the 4th cycle of funding within the Social and Behavioral Research Grants program, VAD is currently reviewing proposals for the Social and Behavioral Research Grants program in a new track dedicated to reaching zero-dose adults and promoting life-course immunization. The Vaccine Acceptance Research Network has also opened a call for abstracts for the VARN2023 conference to facilitate knowledge sharing in these fields of study. Entities such as these generate opportunities to advance vaccination research and identify gaps through partnerships with academics and global health practitioners.