Timing of children's vaccinations in 45 low-income and middle-income countries: an analysis of survey data

doi:10.1016/S0140-6736(09)60317-2

The Lancet

Volume 373, Issue 9674, 2–8 May 2009, Pages 1543-1549

https://doi.org/10.1016/S0140-6736(09)60317-2 Get rights and content

Summary

Background

Vaccinations are often delayed until well after the recommended ages, leaving many children exposed for longer than they should be. We estimated vaccination coverage at different ages, and delays in administration, in 45 low-income and middle-income countries.

Methods

We used data for 217 706 children from Demographic and Health Surveys between 1996 and 2005 (median 2002), which provided data for vaccination of children on the basis of events recorded on vaccination cards and interviews with mothers, with imputation of missing values and survival analysis. We devised an index combining coverage and delay.

Findings

For vaccinated children, the median of the median delays in the 45 countries was 2·3 weeks (IQR 1·4–4·6) for bacille Calmette-Guérin (BCG); 2·4 weeks (1·2–3·3) for diphtheria, tetanus, and pertussis (DTP1); 2·7 weeks (1·7–3·1) for measles-containing vaccine (MCV1); and 6·2 weeks (3·5–8·5) for DTP3. However, in the 12 countries with the longest delays for each vaccination, at least 25% of the children vaccinated were more than 10 weeks late for BCG, 8 weeks for DTP1, 11 weeks for MCV1, and 19 weeks for DTP3. Variation within countries was substantial: the median of the IQRs in the 45 countries for delay in DTP3 was 10·9 weeks, 7·9 weeks for MCV1, 5·4 weeks for BCG, and 5·3 weeks for DTP1. The median of the national coverage rates for DTP1 increased from 57% in children aged 12 weeks to 88% at 12 months, and for DTP3 from 65% at 12 months to 76% at 3 years.

Interpretation

The timeliness of children's vaccination varies widely between and particularly within countries, and published yearly estimates of national coverage do not capture these variations. Delayed vaccination could have important implications for the effect of new and established vaccines on the burden of disease.

Funding

WHO's Initiative for Vaccine Research.

Introduction

Late administration of vaccines has implications for the success of child immunisation programmes. Estimates of WHO and UNICEF vaccination coverage¹ are based on the prevalence of vaccinated children in a specific cohort (eg, 12–23 months for diphtheria, tetanus, and pertussis [DTP] vaccines), or numbers of vaccinations in a specific year divided by the number of surviving infants (or, for bacille Calmette-Guérin [BCG], by the number of births).² These estimates provide little insight into the extent to which vaccinations are administered on time.³ In practice, although a few children might be vaccinated early, many will be vaccinated late4, 5 and the effect of some vaccine programmes on the burden of disease might be reduced if there are delays in protecting children in high-risk groups.⁶ However, vaccination at older ages, or increased intervals between doses, can provide more durable protection.7, 8, 9, 10 Booster doses can offset the limitations of early doses in some respects, but at extra cost. Thus information about the actual timing of vaccination is needed to help policy makers monitor programmes and respond if need be. Two of the WHO/UNICEF Global Immunisation and Vision Strategies (GIVS) are to strengthen monitoring of coverage and to strengthen the analysis of data,¹¹ and improved surveillance of deviation from age-appropriate vaccination has been recommended in both low-income and high-income settings.12, 13, 14

One example of where late administration might cause concern is provided by the new rotavirus programmes. According to a WHO position paper, rotavirus vaccination “should not be initiated for infants aged more than 12 weeks”,¹⁵ because of a potentially increased risk of intussusception, a rare bowel disorder. Whether the new vaccines will provide indirect protection to unvaccinated infants is also uncertain, and the implication is that the safety and benefits of the programme might depend on timely administration. We aimed to estimate vaccination coverage at different ages, and delays in administration, in low-income and middle-income countries.

Section snippets

Study design

The Demographic and Health Surveys (DHS) aim to provide nationally representative data for vaccination of children, on the basis of events recorded on vaccination cards and interviews with mothers. Surveys were administered in 52 countries between 1996 and 2005, and we used the most recent survey for every country. Seven were excluded: four with no data for days of the month of birth, two with fewer than 250 children with complete and valid data for calculation of exact age at each vaccination,

Results

We examined data quality for all children covered by the surveys. Data for the completeness of the dates needed to calculate age at vaccination are given in the webappendix (p 3). When dates of vaccination were provided, they were almost all complete and valid. However, day of the month of birth was missing in about 20% of cases. The older the child, the less likely they were to have a card record of their vaccination (table 1). Furthermore, reported coverage (card plus mother's recall) dropped

Discussion

Variation between countries in vaccination coverage rates is widely reported. In this study we have shown that coverage at 12 months underestimates final coverage, and that adherence to the recommended schedules varies substantially within and between countries.

Our findings are based on survey data. How representative are they? Consistent DHS sampling methods and questionnaires were used in every country, but the survey years varied (1996–2005), so country-specific results are not strictly

References (31)

K Mulholland et al.
Randomised trial of Haemophilus influenzae type-b tetanus protein conjugate for prevention of pneumonia and meningitis in Gambian infants
Lancet
(1997)
MK Akmatov et al.
Timeliness of vaccination and its effect on fraction of vaccinated population
Vaccine
(2008)
BP Hull et al.
Timeliness of childhood immunisation in Australia
Vaccine
(2006)
NS Crowcroft et al.
How best to estimate the global burden of pertussis?
Lancet Infect Dis
(2003)
E Dannetun et al.
Timeliness of MMR vaccination—influence on vaccination coverage
Vaccine
(2004)
EJ Barzilay et al.
Could a single dose of pneumococcal conjugate vaccine in children be effective? Modeling the optimal age of vaccination
Vaccine
(2006)
WHO-UNICEF estimates of coverage
WHO/UNICEF estimates of national immunization coverage, 1980–2004
E Luman et al.
Timeliness of childhood vaccinations in the United States: days unvaccinated and number of vaccines delayed
JAMA
(2005)
M Ndiritu et al.
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
(2006)

U Heiniger et al.

Immunization rates and timely administration in pre-school and school-aged children

Eur J Pediatr

(2006)

WA Orenstein et al.

Diphtheria and tetanus toxoids and pertussis vaccine, combined

LJ Baraff et al.

Immunological response to early and routine DTP immunization in infants

Paediatrics

(1984)

NA Halsey et al.

The efficacy of DTP and oral poliomyelitis immunization schedules initiated from birth to 12 weeks of age

Bull World Health Organ

(1985)

C Belloni et al.

Immunogenicity of a three-component acellular pertussis vaccine administered at birth

Paediatrics

(2003)

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ArticlesTiming of children's vaccinations in 45 low-income and middle-income countries: an analysis of survey data

Summary

Background

Methods

Findings

Interpretation

Funding

Introduction

Section snippets

Study design

Results

Discussion

Lancet

Vaccine

Vaccine

Lancet Infect Dis

Vaccine

Vaccine

WHO-UNICEF estimates of coverage

WHO/UNICEF estimates of national immunization coverage, 1980–2004

Timeliness of childhood vaccinations in the United States: days unvaccinated and number of vaccines delayed

JAMA

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

Immunization rates and timely administration in pre-school and school-aged children

Eur J Pediatr

Diphtheria and tetanus toxoids and pertussis vaccine, combined

Immunological response to early and routine DTP immunization in infants

Paediatrics

The efficacy of DTP and oral poliomyelitis immunization schedules initiated from birth to 12 weeks of age

Bull World Health Organ

Immunogenicity of a three-component acellular pertussis vaccine administered at birth

Paediatrics

Articles
Timing of children's vaccinations in 45 low-income and middle-income countries: an analysis of survey data