Effectiveness of bacillus Calmette-Guerin vaccination history on pulmonary tuberculosis symptoms.

The aim of this study was to explore the effectiveness of BCG vaccination on the severity of clinical symptoms of pulmonary tuberculosis symptoms (PTb) in patients from the northwest and west of Iran.

In a cross sectional study of 358 patients with a diagnosis of PTb, 11 clinical symptoms, including cough, chest pain, dyspnea, sputum, fever, hemoptysis, weight loss, loss of appetite, wheezing, weakness, and fatigue were checked and patients with a score of six or more were placed in the severe clinical symptoms group. BCG vaccination scar and clinical symptoms were examined and recorded.

Of the subjects included in this study, 264 cases (73.7%) had no BCG vaccination scar. Comparison of the severity of clinical symptoms of PTb in patients with BCG vaccine history to those lacking vaccination history revealed lower symptom severity in patients who had been vaccinated (vaccine effectiveness = 95.5%; p < 0.00001).

The results of this study may imply that Adjusting for age sex and smoking status, BCG vaccination decreases the severity of clinical symptoms in patients with PTb. We suggest performing a retrospective cohort study on a larger population.