EVALUATION OF INVALID VACCINE DOSES IN 31 COUNTRIES OF THE WHO AFRICAN REGION

Sunday, 21st of December 2014

"We found that in most African countries a relevant proportion of vaccines were administered at ages or intervals not compliant with established recommendations."

Manas K. Akmatov^{a, b, ,} ,

• Elizabeth Kimani-Murage^c,
• Frank Pessler^b,
• Carlos A. Guzman^d,
• Gérard Krause^{a, e},
• Lothar Kreienbrock^f,
• Rafael T. Mikolajczyk^{a, e}

Highlights

•A systematic evaluation of invalid vaccinations, i.e. vaccinations administered earlier than recommended or with too short intervals between vaccine doses, in countries of the WHO African Region has not been performed yet.

•We found that in most African countries a relevant proportion of vaccines were administered at ages or intervals not compliant with established recommendations.

•Invalid vaccinations were partly associated with individual and with community associated factors.

•Community contextual factors should be considered when planning immunisation services.

Abstract below; full text available to journal subscribers

We examined (a) the fraction of and extent to which vaccinations were administered earlier than recommended (age-invalid) or with too short intervals between vaccine doses (interval-invalid) in countries of the World Health Organisation (WHO) African Region and (b) individual- and community-level factors associated with invalid vaccinations using multilevel techniques. Data from the Demographic and Health Surveys conducted in the last 10 years in 31 countries were used. Information about childhood vaccinations was based on vaccination records (n = 134,442). Invalid vaccinations (diphtheria, tetanus, pertussis [DTP1, DTP3] and measles-containing vaccine (MCV)) were defined using the WHO criteria. The median percentages of invalid DTP1, DTP3 and MCV vaccinations across all countries were 12.1% (interquartile range, 9.4–15.2%), 5.7% (5.0–7.6%), and 15.5% (10.0–18.1%), respectively. Of the invalid DTP1 vaccinations, 7.4% and 5.5% were administered at childs age of less than one and two weeks, respectively. In 12 countries, the proportion of invalid DTP3 vaccinations administered with an interval of less than two weeks before the preceding dose varied between 30% and 50%. In 13 countries, the proportion of MCV doses administered at childs age of less than six months varied between 20% and 45%. Community-level variables explained part of the variation in invalid vaccinations. Invalid vaccinations are common in African countries. Timing of childhood vaccinations should be improved to ensure an optimal protection against vaccine-preventable infections and to avoid unnecessary wastage in these economically deprived countries.

Corresponding author at: Department of Epidemiology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany. Tel.: +49 05316181 3103.

Copyright © 2014 Published by Elsevier Ltd.