Effect of national immunisation campaigns with oral polio vaccine on all-cause mortality in children in rural northern Ghana : 20 years of demographic surveillance cohort data

© 2023 The Authors..

Background: Studies from Guinea-Bissau and Bangladesh have shown that campaigns with oral polio vaccine (C-OPV) may be associated with 25-31% lower child mortality. Between 1996 and 2015, Ghana had 50 national C-OPVs and numerous campaigns with vitamin A supplementation (VAS), and measles vaccine (MV). We investigated whether C-OPVs had beneficial non-specific effects (NSEs) on child survival in northern Ghana.

Methods: We used data from a health and demographic surveillance system in the Navrongo Health Research Centre in rural northern Ghana to examine mortality from day 1-5 years of age. We used Cox models with age as underlying time scale to calculate hazard ratios (HR) for the time-varying covariate "after-campaign" mortality versus "before-campaign" mortality, adjusted for temporal change in mortality, other campaign interventions and stratified for season at risk.

Findings: From 1996 to 2015, 75,610 children were followed for 280,156 person-years between day 1 and 5 years of age. In initial analysis, assuming a common effect across all ages, we did not find that OPV-only campaigns significantly reduced all-cause mortality, the HR being 0.96 (95% CI: 0.88-1.05). However, we subsequently found the HR differed strongly by age group, being 0.92 (0.75-1.13), 1.29 (1.10-1.51), 0.79 (0.66-0.94), 0.67 (0.53-0.86) and 1.03 (0.78-1.36) respectively for children aged 0-2, 3-5, 6-8, 9-11 and above 12 months of age (p < 0.001). Triangulation of the evidence from this and previous studies suggested that increased frequency of C-OPVs and a different historical period could explain these results.

Interpretation: In Ghana, C-OPVs had limited effects on overall child survival. However, triangulating the evidence suggested that NSEs of C-OPVs depend on age of first exposure and routine vaccination programs. C-OPVs had beneficial effects for children that were not exposed before 6 months of age. These non-specific effects of OPV should be exploited to further reduce child mortality.

Funding: DANIDA; Else og Mogens Wedell Wedellsborgs Fond.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:66

Enthalten in:

EClinicalMedicine - 66(2023) vom: 01. Dez., Seite 102322

Sprache:

Englisch

Beteiligte Personen:

Welaga, Paul [VerfasserIn]
Mutua, Martin Kavao [VerfasserIn]
Ahmed Hanifi, Syed Manzoor [VerfasserIn]
Ansah, Patrick [VerfasserIn]
Aaby, Peter [VerfasserIn]
Nielsen, Sebastian [VerfasserIn]

Links:

Volltext

Themen:

Child mortality
Journal Article
Non-specific effects of vaccines
OPV
Oral polio vaccine campaigns
Triangulation

Anmerkungen:

Date Revised 25.12.2023

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.eclinm.2023.102322

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM366344684