Immunisation in the 21st Century: Foundations, Challenges, and Strategic Directions for Global Health
DOI:
https://doi.org/10.14738/assrj.1302.19921Keywords:
Immunization, Vaccines, Public Health, Vaccine Hesitancy, Health Equity, Global Health, Health Systems, Vaccine Safety, Cold Chain Logistics, Universal Health CoverageAbstract
Immunization stands as one of the greatest achievements in global health and development, saving millions of lives each year and reshaping the trajectory of public health. It involves the process of making an individual immune or resistant to a particular disease through the administration of vaccines that stimulate the body’s immune system to recognise and combat pathogens. Historically, immunity could only be acquired by contracting and surviving an infectious disease; however, the development of vaccines has enabled immunity to be safely induced without exposure to the illness itself. Vaccines introduce antigens that mimic those of pathogens, thereby triggering a protective immune response and building immunological memory. Immunization can occur through active or passive mechanisms, while vaccines are broadly classified as live attenuated or inactivated. Despite remarkable global progress, immunization continues to face significant challenges that threaten its sustainability. These include vaccine hesitancy, inequitable access, logistical and infrastructural limitations, and fragmented global coordination. Overcoming these barriers requires a coordinated and multifaceted approach involving governments, international organisations, pharmaceutical companies, civil society, and communities. Strengthening healthcare infrastructure, expanding vaccination across the life course, and integrating immunization into broader health systems are essential to achieving equitable coverage. Sustaining progress also depends on comprehensive public education campaigns that raise awareness about vaccine benefits, counter misinformation, and reinforce public trust in science. Investment in surveillance, cold-chain logistics, and communication strategies will ensure vaccines remain safe, effective, and accessible. Continued global collaboration is vital for maintaining momentum towards universal immunization coverage and achieving the Sustainable Development Goals. Ultimately, immunization represents both a biomedical triumph and a moral imperative — protecting populations, promoting equity, and reaffirming health as a universal human right.
References
Abejegah, C., Obohwemu, K.O. and Mdegela, M., (2024). Clinical manifestations and outcomes of human mpox infection from 1970 to 2023: a systematic literature review. Clinical Infection in Practice, 24, p.100397.
Bassett, M.T., Chen, J.T., & Krieger, N. (2020). "Variation in racial/ethnic disparities in COVID-19 mortality by age in the United States: A cross-sectional study". PLOS Medicine, 17(10), e1003402. Scholar Publishing
Boyce, T. (2019). Towards equity in immunization. European Surveillance, 24(2), 1800204.
Brown, V.B. (2017). Vaccine Logistics and Cold Chain Monitoring. In Handbook of Vaccines (pp. 289-309). Springer.
Chang, A.Y., Riumallo-Herl, C., Perales, N.A., Clark, S., Clark, A., & Constenla, D. (2018). The equity impact vaccines may have on averting deaths and medical impoverishment in developing countries. Health Affairs (Millwood), 37(2), 316–324.
Coalition for Epidemic Preparedness Innovations (CEPI). (2019). Annual report: Building global preparedness. CEPI Secretariat.
Cook, J., Jeuland, M., Maskery, B., Lauria, D., Sur, D., Clemens, J., & Whittington, D. (2009). "Using private demand studies to calculate socially optimal vaccine subsidies in developing countries". Journal of Policy Analysis and Management, 28(1), 6–28.
Donaldson, S.V., Thomas, A.N., Gillum, R.F., & Mehari, A. (2021). "Geographic Variation in Racial Disparities in Mortality from Influenza and Pneumonia in the United States in the Pre-Coronavirus Disease 2019 Era". Chest, 159(6), 2183–2190.
Drolet, M., Benard, E., Perez, N., & Brisson, M. (2019). Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis. Lancet, 394(10197), 497–509.
Dubé, E. (2013). Vaccine Hesitancy: An Overview. Human Vaccines & Immunotherapeutics, 9(8), 1763-1773.
Dubé, E. (2014). Understanding Vaccine Hesitancy in Canada: Results of a Consultation Study by the Canadian Immunization Research Network. PLoS ONE, 9(6), e97674.
Gellin, B.G. (2020). Strengthening Immunization Systems Globally: A Sustainable Solution to Achieve Equity in Health. Vaccine, 38(36), 5793-5795.
Hotez, P.J. (2020). Vaccine Diplomacy: Historical Perspectives and Future Directions. PLoS Neglected Tropical Diseases, 14(9), e0008705.
Hua, Y. and Guanghui, M., (2015) Polymeric micro/nanoparticles: Particle design and potential vaccine delivery applications, Vaccine, 33 (44): 5927-5936. https://doi.org/10.1016/j.vaccine.2015.07.100.
Idowu, T.O., Obohwemu, K.O. and Iyevhobu, K.O., (2024). Knowledge, attitudes and practices of mothers towards childhood vaccination in Lagos State, Nigeria. International Journal of Medical Science and Public Health Research, 5(09), pp.69-100.
Kanter, R. (2021). Challenges in Vaccine Supply: Lessons from the COVID-19 Pandemic. The Lancet, 397(10284), 1883-1884.
Kickbusch, I. (2016). Global Health Diplomacy: Concepts, Issues, Actors, Instruments, Fora and Cases. Springer. p. 54.
Kimberlin, D., Brady, M., & Jackson, M. (2018). Report of the Committee on Infectious Diseases. 31st ed. Itasca, IL: American Academy of Pediatrics, 18, 13–64.
Koplan, J.P. (2009). Towards a Common Definition of Global Health. The Lancet, 373(9679), 1993-
Larson, M. (2014). The State of Vaccine Confidence 2014: Global Insights Through a 67-Country Survey. European BioMedicine, 2(7), 792-796.
McKenna, V.B. (2021). Telemedicine and Digital Health in Immunization: A Review of Current Technologies and Opportunities for Expanded Use. Frontiers in Public Health, 9, 675314.
McQuestion, M. (2017). National legislation and spending on vaccines in Latin America and the Caribbean. Journal of Public Health Policy, 38(1), 3–15.
Page | 122 Scholar Publishing Motupalli, D., Chauhan, R., Obohwemu, K., Sharma, S., Abayomi, G., Osinubi, O., Tayo, O., & Adejuyitan, S. (2025). Evaluating the effectiveness of HPV vaccination in preventing oral and oropharyngeal cancers among men: An epidemiological review. Global Journal of Medical and Pharmaceutical Sciences. European International Journal of Multidisciplinary Research and Management Studies, 4(03), 08–13.
Needham, J. (1999). "Part 6, Medicine". Science and Civilization in China: Volume 6, Biology and Biological Technology. Cambridge: Cambridge University Press. p. 134.
Nnadi, C. (2017). Approaches to vaccination among populations in areas of conflict. Journal of Infectious Disease, 216(1), S368–S372.
Obohwemu, K., Christie-de Jong, F. and Ling, J., (2022). Parental childhood vaccine hesitancy and predicting uptake of vaccinations: a systematic review. Primary Health Care Research & Development, 23, p.e68.
Obohwemu, K., (2024). Maternal attitudes towards childhood vaccination in Delta State, Nigeria. Frontline Medical Sciences and Pharmaceutical Journal, 4(12), pp.43-66.
Obohwemu, K.O., (2025a). Prevalence of Vaccine Hesitancy Towards Childhood Vaccinations Among Parents in the United Kingdom. Frontiers in Medical and Clinical Sciences, 2(10), pp.11-27.
Obohwemu, K.O., (2025b). Predicting COVID-19 Vaccination Intentions Among UK Parents Using Protection Motivation Theory. JORMA International Journal of Health and Social Sciences, 2(2), pp.1-28.
Obohwemu, K.O., Owusuaa-Asante, A.M., Ibiangake, N.F., Abayomi, G.O., Idomeh, J.E., Chauhan, R. and Sharma, S., (2025a). The interplay of ethnicity, education, and employment on maternal attitudes toward childhood vaccination in Nigeria. The American Journal of Medical Sciences and Pharmaceutical Research, 7(01), pp.65-77.
Obohwemu, K.O., Idomeh, J.E., and Chauhan, R., (2025b). Sociodemographic Factors and Maternal Knowledge of Childhood Vaccination in Nigeria. International Journal of Medical Science and Public Health Research, 6(01), pp.7-21.
Obohwemu, K.O., Yakpir, G.M., Idomeh, J.E., Abayomi, G.O., Owusuaa-Asante, M.A., Nwokocha, S.C., Kenneth, I.O., Chauhan, R., Sharma, S., Motupalli, D. and Akadiri, M., (2025c). Barriers and Facilitators of COVID-19 Booster Uptake Among Ethnic Minority Populations in the UK: A Systematic Review. International Research Journal of Medical Sciences and Health Care, 2(05), pp.8-28.
Omoregie, J. and Obohwemu, K.O., (2024). The growing prevalence of mpox and the impact on Mental health: a public health emergency. The American Journal of Social Science and Education Innovations, 6(11), pp.129-133.
Oppenheim, B. (2019). Assessing global preparedness for the next pandemic: development and application of an Epidemic Preparedness Index. British Medical Journal of Global Health, 4(1), e1157.
Patel, M.K., Dumolard, L., Nedelec, Y., Sodha, S., Steulet, C., & Kretsinger, K. (2019). Progress toward regional measles elimination – worldwide, 2000–2018. Weekly Epidemiology Records. 49, 581–600.
Philip, R.K. (2018). Life-course immunization as a gateway to health. Expert Review Vaccines, 17(10), 851–864.
Plotkin, S. (2008). Correlates of vaccine-induced immunity. Clinical Infectious Disease, 47, 401–409.
Plotkin, S. (2003). Vaccines, vaccination, and vaccinology. Journal of Infectious Disease, 187, 1347–
Qazi, S. (2015). Ending preventable child deaths from pneumonia and diarrhoea by 2025. Development of the integrated Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea. Archives of Diseases in Children, 100(1), S23–S28.
Scholar Publishing Rao, P. (2018). Strengthening Primary Healthcare Delivery Systems: A Framework for Improving Immunization Coverage. Journal of Public Health Policy, 39(1), 40-56.
Santoli, J.M. (2021). Effects of the COVID-19 Pandemic on Routine Pediatric Vaccine Ordering and Administration - United States, 2020. MMWR. Morbidity and Mortality Weekly Report, 70(37), 1264-
Shimabukuro, T.T. (2021). COVID-19 Vaccine Safety Monitoring in the US: Current Systems and Efforts to Strengthen Monitoring. Vaccine, 39(11), 1511-1517.
Siegrist, C. (2018). Vaccine immunology. In: Plotkin, S., Orenstein, W., Offit, P., et al., eds. Plotkin’s Vaccines. 7th ed. Elsevier, 18, 16–34.
Silverstein, A.M. (2009). A History of Immunology (2nd ed.). Academic Press. p. 293.
World Health Organization (2016) Global Routine Immunization Strategies and Practices (GRISP): a companion document to the Global Vaccine Action Plan (GVAP). p. 560.
World Health Organization (WHO). (2014) Principles and considerations for adding a vaccine to a national immunization programme. From decision to implementation and monitoring. WHO, Geneva, p. 128.
World Health Organization (WHO). (2019). Promote health, keep the world safe, serve the vulnerable, 1st edn. WHO 13th General Programme of Work 2019–2023. p. 18. World Health Organization. (WHO) (2021). Immunization in Practice: A Practical Guide for Health Staff. WHO Press.
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Copyright (c) 2026 Funke Abolade Adumashi, Kennedy Oberhiri Obohwemu, Gabriel Olaoluwa Abayomi, Iyevhobu Oshiokhayamhe Kenneth, Celestine Emeka Ekwuluo, Festus Ituah
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