Evidence map›Paper›PMID 40359420›Full record

SynthesisPloS one2025

Efficacy of BCG vaccination against COVID-19 in health care workers and non-health care workers: A meta-analysis of randomized controlled trials.

Zhuoyang Xia, Jiahao Meng, Xuanyu Wang, Pan Liu, Yumei Wu, Yilin Xiong, Baimei He, Shuguang Gao

Abstract readMeta-Analysis
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in PloS one, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Article
  3. Article
  4. Review
  5. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Zhuoyang XiaDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Jiahao MengDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Xuanyu WangDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Pan LiuDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Yumei WuDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Yilin XiongDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Baimei HeNational Clinical Research Center of Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Shuguang GaoDepartment of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.ORCID 0000-0003-1135-7876

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe Bacillus Calmette-Guérin (BCG) vaccine has shown potential non-specific protection against infectious diseases through "trained immunity", which may offer cross-protection against viral infections. However, there is no consensus on whether BCG vaccination could prevent COVID-19 or reduce its symptoms.

methodsPubMed, Cochrane Library, Embase and Web of Science were searched for randomized controlled trials on BCG vaccination and COVID-19 prevention, covering studies from the inception of each database to 2 May 2024. We included studies where participants, not infected with COVID-19, were vaccinated with BCG or placebo. We excluded non-randomized trials, studies without full texts, unrelated interventions, and those not reporting relevant outcomes. Clinical data on COVID-19 infection, severity, hospitalization, mortality, and other adverse events, were extracted and analyzed. The DerSimonian-Laird random-effects model and the Cochrane Collaboration's risk of Bias Tool were used for analysis and risk of bias assessment.

resultsA total of 12 RCTs involving 18,086 patients were finally included. For the prophylactic effect of BCG on COVID-19, pooled results showed no statistically significant difference between BCG and placebo (pooled RR 1.02; 95%CI: 0.91-1.14). There was no statistically significant difference between non-health care workers (pooled RR 0.91; 95%CI: 0.67-1.24) and health care workers (pooled RR 1.03; 95%CI: 0.93-1.15). Regarding COVID-19 severity, no significant difference were found for asymptomatic (pooled RR 1.18; 95%CI: 0.81-1.72), mild to moderate (pooled RR 0.99; 95%CI: 0.84-1.17), severe COVID-19 (pooled RR 1.25; 95%CI: 0.92-1.70), hospitalization (pooled RR 0.93; 95%CI: 0.58-1.50) or all-cause mortality (pooled RR 0.60; 95%CI: 0.18-1.95) between BCG and placebo groups. Subgroup analysis also showed no significant difference between BCG and placebo in non-health care workers or health care workers.

conclusionsVaccination of BCG could not effectively prevent COVID-19 infection or decrease COVID-19 symptoms both in non-health care workers and health care workers.

Indexed as

BCG VaccineCOVID-19Health PersonnelHumansRandomized Controlled Trials as TopicSARS-CoV-2VaccinationBCG Vaccine

Identifiers

PMID40359420
PMCPMC12074600

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.