The efficacy of Bacillus Calmette-Guerin vaccinations for the prevention of acute upper respiratory tract infection in the elderly.

AIM to study the efficacy of BCG vaccinations, once a month for 3 consecutive months, in elderly on the prevention of acute upper respiratory tract infection (AURTI), interferon - gamma (IFN-γ) and interleukin (IL)-10 level in the BCG and placebo group and their comparison in the period of the study. METHODS an original, experimental, prospective study with randomly pre-test and post-test design. Subjects were 60-75 years old, divided into BCG and placebo groups. The subjects in the BCG group received BCG vaccination, meanwhile the subjects in the placebo group received solvent for BCG vaccine, once a month for 3 months in succession at the deltoid region for each group. The subjects in both groups were evaluated every 2 weeks for the infiltrate diameter, on the 8th and 12th week for the scar measurements, and every 4 weeks for the prevalence of AURTI. The levels of IFN-γ and IL-10 were done at the initial and the end of the study. Data obtained were the prevalence of AURTI, the infiltrate and scar diameters at the site of BCG vaccination, and the levels of IFN-γ and IL-10. Data collected from January 2010 to June 2010 (6 months) at Internal Medicine Policlinics, Prof.Dr.RD Kandou General Hospital, Manado, North Sulawesi, Indonesia. Statistical analysis was performed using descriptive subject's characteristics, paired and unpaired T test and non-parametric test (Mann-Whitney and Wilcoxon test), and Spearman non-parametric test. RESULTS in comparison between two groups in the period of the study, we found a significant reduction in the BCG group on the prevalence of AURTI and significant increase of IFN-γ level in BCG group compared to the placebo group. There were significant increase of IFN-γ and IL-10 levels in the BCG group compared to the placebo group. There were insignificant increase of IFN-γ and IL-10 levels in the pre- and post-BCG group. The increase of IFN-γ level was positively significant correlated with the increase of the infiltrate and scar diameters in the BCG group. CONCLUSION BCG vaccinations in elderly, once a month for 3 consecutive months, significantly prevent the AURTI and can increase the IFN-γ level as Th1 response and IL-10 as Treg response in the period of the study.