Intravesical BCG

RESEARCH QUESTION: How does prior vaccination with Bacille Calmette-Guerin (BCG) affect the infection with COVID-19?


BCG has been suggested as a protective factor against COVID-19. Before randomized clinical trials read out, a retrospective observational study can provide insight into this hypothesis.

Study Design

The study examines the effect of prior intravesical BCG vaccination on COVID-19 infections. The study involves two study groups (those with and without prior intravesical BCG), as depicted below:

BCG cohort pathways

Confounding factors considered are:

  1. Age
  2. Gender
  3. Comorbidities
  4. Facility (reporting organization)


Index date: January 1, 2020

Study period: Index date to present