Dengue vaccine safety signal: Immune enhancement, waning immunity, or chance occurrence?

Vaccine. 2017 Jun 14;35(27):3452-3456. doi: 10.1016/j.vaccine.2017.05.003. Epub 2017 May 18.

Abstract

A new dengue vaccine was associated with increased risk of hospitalized virologically-confirmed disease during year 3 of follow-up among children age 2-5years. Among hypotheses to explain this finding, we could not distinguish definitively between antibody dependent enhancement, waning immunity, or chance occurrence. However, any theory must account for the following: (a) the signal occurred mainly because of decreased dengue among controls rather than increased dengue among vaccinees; (b) among 48 data points, a statistically significant increase in hospitalization among vaccinated children occurred for only one age group, during one year, and in one region; (c) cumulative risk was similar for vaccinated vs. control children age 2-5years at the end of year 5 and lower for vaccinated vs. control children among older age groups; (d) the protective effect of vaccine against hospitalization decreased from years 1-2 to years 3-5 of follow-up for all age groups and regions.

Keywords: Adverse events following immunization; Clinical trial; Dengue; Immunization; Safety; Vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Dengue / epidemiology*
  • Dengue / prevention & control*
  • Dengue Vaccines / adverse effects*
  • Dengue Vaccines / immunology*
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male

Substances

  • Dengue Vaccines