National immunisation campaigns with oral polio vaccine may reduce all-cause mortality: Analysis of 2004-2019 demographic surveillance data in rural Bangladesh

Sebastian Nielsen; Md Abdul Khalek; Christine Stabell Benn; Peter Aaby; Syed Manzoor Ahmed Hanifi

doi:10.1016/j.eclinm.2021.100886

National immunisation campaigns with oral polio vaccine may reduce all-cause mortality: Analysis of 2004-2019 demographic surveillance data in rural Bangladesh

EClinicalMedicine. 2021 May 24:36:100886. doi: 10.1016/j.eclinm.2021.100886. eCollection 2021 Jun.

Authors

Sebastian Nielsen^{1

2}, Md Abdul Khalek³, Christine Stabell Benn^{1

4}, Peter Aaby^{1

2}, Syed Manzoor Ahmed Hanifi³

Affiliations

¹ Bandim Health Project, OPEN (Odense Patient data Explorative Network), Institute of Clinical Research, WP 9, J. B. Winsløws Vej 9a, 5000 Odense, Denmark.
² Bandim Health Project, Indepth Network, Apartado 861, Bissau.
³ Health System and Population Studies Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, BD 1212, Bangladesh.
⁴ Danish Institute of Advanced Science, Odense University Hospital and University of Southern Denmark, Campusvej 55, 5230Odense, Denmark.

Abstract

Background: West African studies have suggested that national immunisation campaigns with oral polio vaccine (C-OPV) may non-specifically reduce all-cause child mortality rate by 15-25%. We investigated whether C-OPVs had similar non-specific effects in rural Bangladesh from 2004 to 2019.

Methods: Chakaria, is a health and demographic surveillance system (HDSS) in Southern Bangladesh. From 2004-2011 the HDSS covered a random sample of households; from 2012 to 2019 it covered a random sample of villages. Using Cox proportional hazards models, we calculated hazard ratios (HR) comparing mortality for children under 3 years of age after C-OPV versus before C-OPV to assess the effect of receiving a C-OPV. We allowed for different baseline hazard function in the two periods (2004-2011, 2012-2019), with separate models for each period.

Findings: There were 768 deaths (2.1%) amongst 36,176 children. The HR after C-OPV was 0.69 (95% confidence interval: 0.52-0.90). National campaigns providing vitamin A or measles vaccine did not have similar effects. Each additional dose of C-OPV was associated with a reduction in the mortality rate by 6% (-2 to 13%). The number needed to treat with C-OPV to save one life between 0 and 35 months of age was 88 (81-96).

Interpretation: This is the fourth study to show that C-OPV has beneficial non-specific effects on child survival. All studies have shown a beneficial effect of C-OPV on child health. Stopping OPV as planned after polio eradication without any mitigation plan could have detrimental effects for overall child health in low-income countries.

Funding: The Chakaria HDSS was funded by international sponsors. No sponsor had any influence on the preparation of the article.

Keywords: Bangladesh; Campaigns; Child mortality; Eradication; Non-specific effects of vaccines; OPV; Oral polio vaccine.