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Out-of-sequence DTP and measles vaccinations and child mortality in Guinea-Bissau: a reanalysis.
- Source :
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BMJ open [BMJ Open] 2019 Sep 05; Vol. 9 (9), pp. e024893. Date of Electronic Publication: 2019 Sep 05. - Publication Year :
- 2019
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Abstract
- Objectives: To assess whether the sequence of diphtheria-tetanus-pertussis vaccine (DTP) and measles vaccine (MV) was associated with child survival in a dataset previously used to assess non-specific effects of vaccines with no consideration of vaccination sequence.<br />Design: Prospective cohort study analysed using the landmark approach.<br />Setting: Bandim Health Project's Health and Demographic Surveillance System covering 100 village clusters in rural Guinea-Bissau. The recommended vaccination schedule was BCG and oral polio vaccine (OPV) at birth, DTP and OPV at 6, 10 and 14 weeks, MV at 9 months and booster DTP and OPV at 18 months of age.<br />Participants: Children aged 9-17 months (main analysis) and 18-35 months (secondary analysis: age of booster DTP) with vaccination status assessed between April 1991 and April 1996.<br />Methods: Survival during the 6 months after assessing vaccination status was compared by vaccination sequence in Cox-proportional hazards models with age as underlying time. Analyses were stratified by sex and village cluster.<br />Main Outcome Measure: Mortality rate ratio (MRR) for out-of-sequence vaccinations compared with in-sequence vaccinations.<br />Results: Among children aged 9-17 months, 60% of observations (3574/5937) were from children who had received both MV and DTP. Among these, 1590 observations were classified as in-sequence vaccinations (last DTP before MV), and 1984 observations were out-of-sequence vaccinations (1491: MV with DTP and 493: MV before DTP). Out-of-sequence vaccinations were associated with higher mortality than in-sequence vaccinations (MRR 2.10, 95% CI 1.07 to 4.11); the MRR was 2.30 (95% CI 1.15 to 4.58) for MV with DTP and 1.45 (95% CI 0.50 to 4.22) for DTP after MV. Associations were similar for boys and girls (p=0.77). Between 18 and 35 months the mortality rate increased among children vaccinated in-sequence and the differential effect of out-of-sequence vaccinations disappeared.<br />Conclusion: Out-of-sequence vaccinations may increase child mortality. Hence, sequence of vaccinations should be considered when planning vaccination programmes or introducing new vaccines into the current vaccination schedule.<br />Competing Interests: Competing interests: None declared.<br /> (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Subjects :
- Child
Child, Preschool
Female
Guinea-Bissau
Humans
Infant
Male
Proportional Hazards Models
Prospective Studies
Child Mortality
Diphtheria-Tetanus-Pertussis Vaccine therapeutic use
Immunization Schedule
Immunization, Secondary statistics & numerical data
Vaccination statistics & numerical data
Subjects
Details
- Language :
- English
- ISSN :
- 2044-6055
- Volume :
- 9
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- BMJ open
- Publication Type :
- Academic Journal
- Accession number :
- 31492774
- Full Text :
- https://doi.org/10.1136/bmjopen-2018-024893