Contrasting female-male mortality ratios after routine vaccinations with pentavalent vaccine versus measles and yellow fever vaccine. A cohort study from urban Guinea-Bissau.

Tuesday, 2nd of August 2016

Vaccine. 2016 Jul 27. pii: S0264-410X(16)30617-X. doi: 10.1016/j.vaccine.2016.07.034. [Epub ahead of print]

Contrasting female-male mortality ratios after routine vaccinations with pentavalent vaccine versus measles and yellow fever vaccine. A cohort study from urban Guinea-Bissau.

Fisker AB¹ Biering-Sørensen S² Lund N³ Djana Q⁴ Rodrigues A⁵ Martins CL⁶ Benn CS⁷.

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Abstract

BACKGROUND:

In addition to protection against the target diseases vaccines may have non-specific effects (NSEs). Measles vaccine (MV) has beneficial NSEs providing protection against non-measles deaths most so for girls. By contrast though protecting against diphtheria tetanus and pertussis DTP vaccine is associated with increased female mortality relative to male mortality. In 2008 Guinea-Bissau replaced DTP with the DTP-containing pentavalent vaccine (Penta; DTP-H. influenza type B-Hepatitis B) at 6 10 and 14weeks and yellow fever vaccine (YF) was to be given with MV. We investigated possible sex-differential mortality rates following Penta and MV+YF vaccination.

METHODS:

Bandim Health Project (BHP) registers vaccines given by the three government health centres in the study area and vital status through demographic surveillance. We assessed the association between sex and mortality by vaccination status in Cox proportional hazards models with age as underlying timescale. Follow-up was censored at a subsequent vaccination contact or after 6months of follow-up.

RESULTS:

Between September 2008 and April 2011 we registered 23448 vaccination contacts for children aged 42-365days; 17313 were for Penta and 3028 for MV (2907 co-administered with YF). During follow-up 112 children died. The female/male mortality rate ratio was 1.73 (1.11-2.70) following Penta and 0.38 (0.12-1.19) after MV (p=0.02 for same effect). Adjusting for maternal education or weight-for-age at the time of vaccination did not change the estimates.

CONCLUSION:

Penta appears to have the same negative effects on mortality as those seen for DTP. Assessing post-vaccination mortality for boys and girls is necessary to improve the vaccination programme.

Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.