BCG Vaccination of Health Care Workers Does Not Reduce SARS-CoV-2 Infections nor Infection Severity or Duration: a Randomized Placebo-Controlled Trial
Juana Claus, Thijs ten Doesschate, Cheyenne Gumbs, Cornelis H. van Werkhoven, Thomas W. van der Vaart, Axel B. Janssen, Gaby Smits, Rob van Binnendijk, Fiona van der Klis, Debbie van Baarle, Fernanda L. Paganelli, Helen L. Leavis, Lilly M. Verhagen, Simone A. Joosten, Marc J. M. Bonten, Mihai G. Netea, Janneke van de Wijgert, Wim Boersma, Özlem Bulut, Reinout van Crevel, Priya A. Debisarun, Jacobien J. Hoogerwerf, Marien de Jonge, Angèle P. M. Kerckhoffs, Edward F. Knol, Jan Pieter R. Koopman, Vincent P. Kuiper, Arief Lalmohamed, Simone J.C.F.M. Moorlag, Stefan Nierkens, Cees van Nieuwkoop, Jaap ten Oever, Tom H. M. Ottenhoff, Nienke Paternotte, Bart Rijnders, Anna H.E. Roukens, Esther Taks, Janetta Top, Karin Veerman, Andreas Voß, Rob J. L. Willems
Abstract
While several BCG trials in adults were conducted during the 2019 coronavirus disease epidemic, our data set is the most comprehensive to date, because we included serologically confirmed infections in addition to self-reported positive SARS-CoV-2 test results. We also collected data on symptoms for every day during the 1-year follow-up period, which enabled us to characterize infections in detail. We found that BCG vaccination did not reduce SARS-CoV-2 infections nor infection duration or severity but may have enhanced SARS-CoV-2 antibody production during SARS-CoV-2 infection in the first 3 months after vaccination. These results are in agreement with other BCG trials that reported negative results (but did not use serological endpoints), except for two trials in Greece and India that reported positive results but had few endpoints and included endpoints that were not laboratory confirmed. The enhanced antibody production is in agreement with prior mechanistic studies but did not translate into protection from SARS-CoV-2 infection.