Adverse effects of BCG vaccination; mainly BCG infection

Area of Science:

• Immunology
• Vaccinology
• Public Health

Background:

• Bacille Calmette-Guérin (BCG) is a widely used vaccine for tuberculosis prevention.
• Understanding BCG vaccine's adverse effects is crucial for safe and effective immunization programs.
• Adverse events range from mild local reactions to rare, severe systemic complications.

Purpose of the Study:

• To comprehensively review the local and systemic adverse effects associated with BCG vaccination.
• To identify risk factors influencing the occurrence and severity of BCG vaccine adverse events.
• To provide guidance on minimizing BCG vaccine-related risks.

Main Methods:

• Systematic review of literature on BCG vaccine adverse effects.
• Analysis of reported cases of local and systemic reactions.
• Identification and categorization of risk factors, including vaccine characteristics, administration methods, and patient-specific factors.

Main Results:

• Local adverse effects (ulceration, abscesses, adenitis) are generally mild but can be persistent.
• Systemic adverse effects, though rare, can be life-threatening (e.g., osteitis, disseminated BCG infection, anaphylaxis).
• Risk factors include intradermal route, vaccine strain, high doses, younger age at vaccination, and immunodeficiency (HIV, immunosuppressive therapy).

Conclusions:

• BCG vaccine adverse effects are generally mild and inversely related to age.
• Severe systemic BCG infection is a significant risk in immunocompromised individuals.
• Minimizing risks involves careful patient screening for contraindications and meticulous vaccine administration.