Loharikar A , Dumolard L , Chu S , Hyde T , Goodman T , Mantel C , 2016. Status of new vaccine introduction – worldwide, September 2016. MMWR Morb Mortal Wkly Rep 65: 1136–1141.
Gandhi G , 2015. Charting the evolution of approaches employed by the Global Alliance for Vaccines and Immunizations (GAVI) to address inequities in access to immunization: a systematic qualitative review of GAVI policies, strategies and resource allocation mechanisms thr. BMC Public Health 15: 1198.
Wang SA et al. 2013. New vaccine introductions: assessing the impact and the opportunities for immunization and health systems strengthening. Vaccine 31: 762–773.
Mihigo R , Okeibunor J , Anya B , Mkanda P , Zawaira F , 2017. Challenges of immunization in the African Region. Pan Afr Med J 27 (Suppl 3): 12.
World Health Organization , 2020. Geneva, Switzerland: WHO.
Phillips DE , Dieleman JL , Lim SS , Shearer J , 2017. Determinants of effective vaccine coverage in low and middle-income countries: a systematic review and interpretive synthesis. BMC Health Serv Res 17: 681.
Guerra FA , 2007. Delays in immunization have potentially serious health consequences. Paediatr Drugs 9: 143–148.
Mutua MK et al. 2020. Complete and on-time routine childhood immunisation: determinants and association with severe morbidity in urban informal settlements, Nairobi, Kenya. Ann Hum Biol 47: 132–141.
Burchett HED et al. 2014. The impact of introducing new vaccines on the health system: case studies from six low- and middle-income countries. Vaccine 32: 6505–6512.
Torres-Rueda S et al. 2015. New pneumococcal conjugate vaccine introductions in four sub-saharan african countries: a cross-country analysis of health systems’ impacts. Afr Health Sci 15: 868–877.
de Oliveira LH , Trumbo SP , Ruiz Matus C , Sanwogou NJ , Toscano CM , 2016. Pneumococcal conjugate vaccine introduction in Latin America and the Caribbean: progress and lessons learned. Expert Rev Vaccines 15: 1295–1304.
de Oliveira LH et al. 2013. Systematic documentation of new vaccine introduction in selected countries of the Latin American Region. Vaccine 31 (Suppl 3): C114–C122.
WHO , 2020. Recommendations for Routine Immunization Schedules, Summary Tables. Geneva, Switzerland: World Health Organization. Available at: https://www.who.int/teams/immunization-vaccines-and-biologicals/policies/who-recommendations-for-routine-immunization—summary-tables. Accessed February 22, 2021.
Sambala EZ , Wiyeh AB , Ngcobo N , Machingaidze S , Wiysonge CS , 2020. New vaccine introductions in Africa before and during the decade of vaccines – are we making progress? Vaccine 37: 3290–3295.
WHO/UNICEF, 2020. Global Summary of Immunization Schedules. WHO/UNICEF Joint Reporting Form. Available at: https://apps.who.int/immunization_monitoring/globalsummary/schedules. Accessed February 22, 2021.
Shearer JC , Walker DG , Risko N , Levine OS , 2012. The impact of new vaccine introduction on the coverage of existing vaccines: a cross-national, multivariable analysis. Vaccine 30: 7582–7587.
Ndiritu M et al. 2006. Immunization coverage and risk factors for failure to immunize within the Expanded Programme on Immunization in Kenya after introduction of new Haemophilus influenzae type b and hepatitis b virus antigens. BMC Public Health 6: 1–8.
Hull BP , Menzies R , Macartney K , McIntyre PB , 2013. Impact of the introduction of rotavirus vaccine on the timeliness of other scheduled vaccines: the Australian experience. Vaccine 31: 1964–1969.
Zou G et al. 2017. Effects of the introduction of new vaccines in Guinea-Bissau on vaccine coverage, vaccine timeliness, and child survival: an observational study. Vaccine 9: 1–12.
Sadoh AE , Nwaneri DU , Ogboghodo BC , Sadoh WE , 2016. Effect of introduction of pentavalent vaccine as replacement for Diphtheria-Tetanus-Pertussis and Hepatitis B vaccines on vaccination uptake in a health facility in Nigeria. Vaccine 34: 2722–2728.
Beguy D et al. 2015. Health and demographic surveillance system profile: the Nairobi Urban Health and Demographic Surveillance System (NUHDSS). Int J Epidemiol 44: 462–471.
Beguy D , Bocquier P , Zulu EM , 2010. Circular migration patterns and determinants in Nairobi slum settlements. Demogr Res 23: 549–586.
Emina J et al. 2011. Monitoring of health and demographic outcomes in poor urban settlements: evidence from the Nairobi Urban Health and Demographic Surveillance System. J Urban Health 88: S200–S218.
Mutua MK , Kimani-Murage E , Ettarh RR , 2011. Childhood vaccination in informal urban settlements in Nairobi, Kenya: who gets vaccinated? BMC Public Health 11: 6.
Beguy D et al. 2015. Health and Demographic Surveillance System Profile: the Nairobi Urban Health and Demographic Surveillance System (NUHDSS). Int J Epidemiol 44: 462–471.
Wamukoya M , Kadengye DT , Iddi S , Chikozho C , 2020. The Nairobi Urban Health and Demographic Surveillance of slum dwellers, 2002–2019: value, processes, and challenges. Glob Epidemiol 2: 100024.
Olayinka F , Ewald L , Steinglass R , 2017. Beyond new vaccine introduction: the uptake of pneumococcal conjugate vaccine in the African Region. Pan Afr Med J 27 (Suppl 3): 3.
Kallenberg J et al. 2016. Gavi’s transition policy: moving from development assistance to domestic financing of immunization programs. Health Aff (Millwood) 35: 250–258.
Ojal J et al. 2019. Sustaining pneumococcal vaccination after transitioning from Gavi support: a modelling and cost-effectiveness study in Kenya. Lancet Glob Heal 7: e644–e654.
Republic of Kenya Ministry of Public Health and Sanitation, Division of Vaccines and Immunizations , 2013. Comprehensive Multi-Year Plan 2011–2015. Nairobi, Kenya: WHO. Available at: https://www.who.int/immunization/programmes_systems/financing/countries/cmyp/Kenya_cMYP_doc.pdf. Accessed May 3, 2021.
Bocquier P , Beguy D , Zulu EM , Muindi K , Konseiga A , Yé Y , 2011. Do migrant children face greater health hazards in slum settlements? Evidence from Nairobi, Kenya. J Urban Health 88(Suppl 2): 266–281.
Masters NB , Wagner AL , Carlson BF , Boulton ML , 2018. Vaccination timeliness and co-administration among Kenyan children. Vaccine 36: 1353–1360.
Masters NB , Wagner AL , Boulton ML , 2019. Vaccination timeliness and delay in low- and middle-income countries: a systematic review of the literature, 2007–2017. Hum Vaccin Immunother 15: 2790–2805.
Mutua MK , Kimani-Murage E , Ngomi N , Ravn H , Mwaniki P , Echoka E , 2016. Fully immunized child: coverage, timing and sequencing of routine immunization in an urban poor settlement in Nairobi, Kenya. Trop Med Health 44: 1–12.
WHO , 2020. Leave No One Behind: Guidance for Planning and Implementing Catch-up Vaccination. Geneva, Switzerland: World Health Organization.
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New vaccine introduction accompanied by social mobilization activities could contribute to improved routine immunization timeliness. This study assesses the impact of Kenya’s introduction of pneumococcal conjugate vaccine (PCV) on the timeliness of routine childhood vaccination in two informal, urban settlements in Nairobi. Data collected from 2007 to 2015 as part of a demographic surveillance system were used to estimate annual vaccination delays of ≥ 4 weeks among children aged 12–23 months in the period before and after the introduction of PCV in Kenya. Binomial segmented regression models using generalized estimating equations examined the association between vaccine introduction and timeliness of routine immunization. Over half of all children vaccinated in the two urban areas received one or more doses ≥ 4 weeks after the recommended age. The timeliness of routine immunization showed slight improvements or nonsignificant changes during the years following PCV introduction compared with the preceding years (adjusted prevalence ratio [aPR]: 0.67, 95% CI: 0.45–0.99 for Bacille Calmette-Guerin receipt; aPR: 0.59, 95% CI: 0.41–0.83 for third dose Pentavalent receipt; aPR: 1.19, 95% CI: 0.99–1.42 for measles). However, as of 2015, delayed vaccination remained prevalent in children, particularly among the poorest residing in the settlements. Many sub-Saharan African countries have introduced new life-saving vaccines into their routine childhood immunization schedule. Additional evidence regarding the positive or neutral influence of new vaccine introduction on the performance of delivery systems provides further justification to sustain the inclusion of these more costly vaccines in the immunization schedule.
Financial support: This work was supported by the African Population and Health Research Center and the Office of Global Public Health at the University of Michigan to conduct research on-site in Nairobi, Kenya.
Authors’ addresses: Cara Bess Janusz, School of Public Health, University of Michigan, Ann Arbor, MI, and The Institute of Global Health Equity, University of Michigan, Ann Arbor, MI, E-mail: email@example.com. Martin K. Mutua, Data Measurements and Evaluation, African Population and Health Research Center, Nairobi, Kenya, E-mail: firstname.lastname@example.org. Abram L. Wagner, University of Michigan, Ann Arbor, MI, E-mail: email@example.com. Matthew L. Boulton, Infectious Disease Division, Michigan Medicine, Ann Arbor, MI, E-mail: firstname.lastname@example.org.