Simultaneous vaccination with MMR and DTaP-IPV-Hib and rate of hospital admissions with any infections: A nationwide register based cohort study.

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Vaccine. 2016 Nov 10. pii: S0264-410X(16)31033-7. doi: 10.1016/j.vaccine.2016.11.005. [Epub ahead of print]

Simultaneous vaccination with MMR and DTaP-IPV-Hib and rate of hospital admissions with any infections: A nationwide register based cohort study.

Sørup S¹ Benn CS² Poulsen A³ Krause TG⁴ Aaby P⁵ Ravn H².

Author information

• ¹Research Center for Vitamins and Vaccines (CVIVA) Bandim Health Project Statens Serum Institut Copenhagen Denmark. Electronic address: sgs@ssi.dk.
• ²Research Center for Vitamins and Vaccines (CVIVA) Bandim Health Project Statens Serum Institut Copenhagen Denmark; OPEN Odense Patient Data Explorative Network Odense University Hospital/Department of Clinical Research University of Southern Denmark Odense Denmark.
• ³Department of Paediatrics and Adolescent Medicine Rigshospitalet Copenhagen Denmark.
• ⁴Department of Infectious Disease Epidemiology Statens Serum Institut Copenhagen Denmark.
• ⁵Research Center for Vitamins and Vaccines (CVIVA) Bandim Health Project Statens Serum Institut Copenhagen Denmark; Bandim Health Project Indepth Network Bissau Guinea-Bissau.

Abstract

BACKGROUND:

In Denmark live measles mumps and rubella vaccine (MMR) is associated with a reduced risk of infectious disease admissions particularly for lower respiratory tract infections. In low-income countries simultaneous vaccination (i.e. vaccination at the same visit) with live and inactivated vaccines may increase child mortality compared with the live vaccine alone. We examined the hypothesis that simultaneous administration of MMR and the inactivated DTaP-IPV-Hib vaccine compared with MMR alone is associated with higher incidence of infectious disease admissions.

METHODS:

Nationwide retrospective register based cohort study of 520859 children born in Denmark 1997-2006 who were followed from 15months to 4years of age. Incidence rate ratios (IRRs) of hospital admissions were estimated by Cox regression and adjusted for background factors including exact age.

RESULTS:

By 2years of age 4965 children had simultaneous MMR and DTaP-IPV-Hib as their most recent vaccination. Compared with MMR alone simultaneous administration was associated with a higher rate of lower respiratory tract infections (adjusted incidence rate ratio (IRR) 1.27; 95% confidence interval (CI) 1.13-1.42). There was no effect on other infections. Overall simultaneous administration was associated with a 7% (95% CI 0-15%) increase in infectious disease admissions.

CONCLUSIONS:

Simultaneous administration of MMR and DTaP-IPV-Hib compared with MMR alone may increase the rate of hospital admissions related to lower respiratory tract infections. These findings require replication in other high-income settings.