Century Old BCG Vaccine Shields Against Long COVID Symptoms

A clinical trial reveals promising insights into the role of BCG immunotherapy in reducing long COVID complications.

Topline

Administering the Bacillus Calmette-Guérin (BCG) vaccine during active COVID-19 infection may reduce the risk of long COVID symptoms, especially in cognitive and cardiopulmonary domains.

Study Details

The BCG vaccine, known for its role in tuberculosis prevention, has been explored as a therapeutic intervention for COVID-19. A phase 3 clinical trial investigated its effects on long COVID, a condition marked by persistent symptoms beyond the acute infection phase. Researchers hypothesized that the vaccine's immunomodulatory effects could reduce the burden of long COVID symptoms.

Methodology

The trial, initiated in 2020, enrolled 393 adults with mild to moderate COVID-19 symptoms. Participants were randomly assigned to receive either 0.1 mL of intradermal BCG or a saline placebo within 14 days of symptom onset. Follow-up assessments were conducted at 7, 14, 21, and 45 days, and at 6 and 12 months. Researchers evaluated the prevalence of long COVID symptoms, such as cognitive dysfunction, sleep disturbances, and sensory issues.

Key Findings

• At 6 months, BCG recipients showed significantly fewer hearing issues compared to the placebo group (OR, 0.26; P = .044).

• By 12 months, recipients experienced reduced sleep disturbances (P = .027), memory problems (P = .009), and concentration difficulties (P = .009).

• Cognitive and vision-related issues were also less frequent among BCG recipients, alongside a lower long-COVID symptom score (P = .002).

• Male recipients benefitted most significantly, showing reduced cognitive and cardiopulmonary dysfunction scores. Interestingly, BCG reduced hair loss in men (P = .031) but slightly increased it in women, though not statistically significant.

Implications for Practice

The findings highlight BCG immunotherapy's potential as a treatment for long COVID rather than a preventive vaccine in healthy individuals. For healthcare providers, these results suggest a possible new tool to mitigate long-term complications in COVID-19 patients. From a patient perspective, the study offers hope for improving quality of life after recovery. Future research should explore sex-specific responses to BCG and optimize its therapeutic applications.