Field challenges to measles elimination in the Democratic Republic of the Congo

R M Coulborn; F Nackers; C Bachy; K Porten; H Vochten; E Ndele; M Van Herp; E Bibala-Faray; S Cohuet; I Panunzi

doi:10.1016/j.vaccine.2020.02.029

Field challenges to measles elimination in the Democratic Republic of the Congo

Vaccine. 2020 Mar 17;38(13):2800-2807. doi: 10.1016/j.vaccine.2020.02.029. Epub 2020 Feb 25.

Authors

R M Coulborn¹, F Nackers², C Bachy³, K Porten², H Vochten⁴, E Ndele⁴, M Van Herp³, E Bibala-Faray⁵, S Cohuet², I Panunzi³

Affiliations

¹ Epicentre, Paris, France. Electronic address: rebecca.coulborn@epicentre.msf.org.
² Epicentre, Paris, France.
³ Médecins Sans Frontières, Brussels, Belgium.
⁴ Médecins Sans Frontières, Kinshasa, Democratic Republic of the Congo.
⁵ Ministry of Public Health, Maniema, Democratic Republic of the Congo.

PMID: 32111528
DOI: 10.1016/j.vaccine.2020.02.029

Abstract

Background: During a measles epidemic, the Ministry of Public Health (MOH) of the Democratic Republic of the Congo conducted supplementary immunization activities (2016-SIA) from August 28-September 3, 2016 throughout Maniema Province. From October 29-November 4, 2016, Médecins Sans Frontières and the MOH conducted a reactive measles vaccination campaign (2016-RVC) targeting children six months to 14 years old in seven health areas with heavy ongoing transmission despite inclusion in the 2016-SIA, and a post-vaccination survey. We report the measles vaccine coverage (VC) and effectiveness (VE) of the 2016-SIA and VC of the 2016-RVC.

Methods: A cross-sectional VC cluster survey stratified by semi-urban/rural health area and age was conducted. A retrospective cohort analysis of measles reported by the parent/guardian allowed calculation of the cumulative measles incidence according to vaccination status after the 2016-SIA for an estimation of crude and adjusted VE.

Results: In November 2016, 1145 children (6-59 months old) in the semi-urban and 1158 in the rural areas were surveyed. Post-2016-SIA VC (documentation/declaration) was 81.6% (95%CI: 76.5-85.7) in the semi-urban and 91.0% (95%CI: 84.9-94.7) in the rural areas. The reported measles incidence in October among children less than 5 years old was 5.0% for 2016-SIA-vaccinated and 11.2% for 2016-SIA-non-vaccinated in the semi-urban area, and 0.7% for 2016-SIA-vaccinated and 4.0% for 2016-SIA-non-vaccinated in the rural area. Post-2016-SIA VE (adjusted for age, sex) was 53.9% (95%CI: 2.9-78.8) in the semi-urban and 78.7% (95%CI: 0-97.1) in the rural areas. Post 2016-RVC VC (documentation/declaration) was 99.1% (95%CI: 98.2-99.6) in the semi-urban and 98.8% (95%CI: 96.5-99.6) in the rural areas.

Conclusions: Although our VE estimates could be underestimated due to misclassification of measles status, the VC and VE point estimates of the 2016-SIA in the semi-urban area appear suboptimal, and in combination, could not limit the epidemic. Further research is needed on vaccination strategies adapted to urban contexts.

Keywords: Democratic Republic of the Congo; Mass vaccination; Measles vaccination; Vaccination coverage; Vaccine effectiveness.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Child
Child, Preschool
Cross-Sectional Studies
Democratic Republic of the Congo / epidemiology
Humans
Immunization Programs
Infant
Measles Vaccine / administration & dosage*
Measles* / epidemiology
Measles* / prevention & control
Retrospective Studies
Vaccination Coverage / statistics & numerical data*

Substances

Measles Vaccine