Revaccination with measles-mumps-rubella vaccine and hospitalization for infection in Denmark and Sweden – An interrupted time-series analysis

Signe Sørup*, Hélène Englund, Ida Laake, Heta Nieminen, Lise Gehrt, Berit Feiring, Lill Trogstad, Adam Roth, Christine Stabell Benn

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

3 Downloads (Pure)

Abstract

Background: In a previous cohort study of 4-year-old Danish children, revaccination with the live measles-mumps-rubella vaccine (MMR) was associated with a 16% reduction in the rate of hospitalization lasting two days or longer for non-measles-mumps-rubella infections. Aim: To examine if the introduction of revaccination with MMR at 4 years of age in Denmark (spring 2008) and at 7–9 years of age in Sweden (autumn 2009), at a time when there was virtually no measles, mumps or rubella cases, was associated with a reduction in the rate of hospitalization-for-infection lasting two days or longer at the population level. Methods: We included 4-year-olds in Denmark and 7–9-year-olds in Sweden. We obtained the number of hospitalization-for-infection lasting two days or longer from nationwide hospital registers. Person-years at risk were approximated from population statistics for each season and year. We performed an interrupted time series analysis using Poisson regression to estimate the change in hospitalization incidence rates following the introduction of MMR revaccination, adjusting for seasonality. We also performed analyses with control series (3-year-olds in Denmark and 4-year-olds in Sweden). Results: Comparing the incidence of hospitalization-for-infection lasting two days or longer after the introduction of MMR revaccination with the expected level without an introduction of MMR revaccination resulted in an incidence rate ratio of 1.07 (95% confidence interval [CI] = 0.89–1.28) for 4-year-olds in Denmark and 0.89 (95% CI = 0.77–1.02) for 7–9-year-olds in Sweden in analyses without controls. Analyses with controls gave similar results. Conclusion: This population-level study of the introduction of MMR revaccination in Denmark and Sweden had inadequate power to confirm or refute the findings from an individual-level Danish study of an association between MMR revaccination and a lower incidence rate of hospitalization-for-infection lasting two days or longer.

Original languageEnglish
JournalVaccine
ISSN0264-410X
DOIs
Publication statusE-pub ahead of print - 29. Jan 2021

Keywords

  • Heterologous immunity
  • Hospitalization
  • Interrupted time-series analysis
  • Measles-mumps-rubella vaccine
  • Non-specific effects of vaccines
  • Vaccination programme

Fingerprint

Dive into the research topics of 'Revaccination with measles-mumps-rubella vaccine and hospitalization for infection in Denmark and Sweden – An interrupted time-series analysis'. Together they form a unique fingerprint.

Cite this