Healthcare Workers (HCWs) and non-HCWs reaction to Bacillus Calmette-Guérin (BCG) in the BATTLE trial

Mehrsa Jalalizadeh; Patrícia A F Leme; Keini Buosi; Franciele A V Dionato; Luciana S B Dal Col; Cristiane F Giacomelli; Leonardo O Reis

doi:10.1016/j.vaccine.2023.09.031

Healthcare Workers (HCWs) and non-HCWs reaction to Bacillus Calmette-Guérin (BCG) in the BATTLE trial

Vaccine. 2023 Oct 20;41(44):6599-6606. doi: 10.1016/j.vaccine.2023.09.031. Epub 2023 Sep 22.

Authors

Mehrsa Jalalizadeh¹, Patrícia A F Leme¹, Keini Buosi¹, Franciele A V Dionato¹, Luciana S B Dal Col¹, Cristiane F Giacomelli¹, Leonardo O Reis²

Affiliations

¹ UroScience, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, Sao Paulo, Brazil.
² UroScience, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, Sao Paulo, Brazil; Pontifical Catholic University of Campinas, PUC-Campinas, Sao Paulo, Brazil. Electronic address: reisleo.l@gmail.com.

PMID: 37743116
DOI: 10.1016/j.vaccine.2023.09.031

Abstract

Objectives: Healthcare workers (HCWs) may have different response to Bacillus Calmette-Guérin (BCG) vaccination due to previous occupational exposure to Mycobacterium particles. We report subgroup analysis of the BATTLE trial, comparing BCG effects in HCWs vs non-HCWs. This was a secondary analysis of a trial.

Methods: The BATTLE trial was a double-blind placebo-controlled phase III clinical trial that investigated BCG revaccinating adults who were recently infected with SARS-CoV-2 virus. BCG and placebo recipients were sub-grouped based on regular occupational contact with patients into HCWs (48 BCG and 50 placebo) and non-HCWs (124 BCG and 134 placebo). Weekly COVID-19 symptom progression and injection site reactions were compared between subgroups on weeks one, two, three, and six follow-ups.

Results: HCWs were more likely to complain of itching on the injection site early after injection (OR = 2.5, p = 0.049). They developed peeling and crusting on the site of injection faster than non-HCWs (during the second week, p = 0.033 and 0.040, OR = 3.3 and 2.7, respectively). HCWs were also more likely to maintain their papule or develop a late onset pustule during later weeks (weeks four and six, p = 0.024 and 0.006, OR = 2.2 and 8.6, respectively). In terms of COVID-19 symptom progression, recovery from anosmia was more likely in the non-HCWs who received BCG (week six, p_{Holm's corrected} = 0.002, OR = 3.3).

Conclusion: HCWs' local reaction to BCG injection was slightly more rapid and more intense, possibly due to their occupational exposure. BCG may also ameliorate COVID-19 induced inflammation and anosmia in non-HCWs but not HCWs. Therefore, HCWs might be less likely to benefit from BCG vaccination.

Clinicaltrials: gov register number NCT04369794.

Keywords: Anosmia; BATTLE; BCG; COVID-19; Healthcare workers; Olfactory dysfunction; Randomized clinical trial; SARS-CoV-2; Vaccine.

Associated data

ClinicalTrials.gov/NCT04369794