Quality Assessment and Subtype Monitoring of BCG Tokyo 172-1 Vaccine Produced by Queen Saovabha Memorial Institute During 2015–2021

Quality Assessment of BCG Tokyo 172-1 Vaccine Produced by Queen Saovabha

Abstract

        BCG vaccine has been included in Thailand’s Expanded Program on Immunization (EPI) for all Thai newborns. Therefore, quality control must be determined in every production batch to ensure the quality and efficacy of the vaccines. The quality assessment and safety of BCG Tokyo 172-1 vaccine were investigated on 133 lots of vaccines manufactured by Queen Saovabha Memorial Institute during 2015–2021. The testing results of appearance, identity, moisture content, potency and stability revealed that all lots of BCG vaccines met the product specifications and the standard requirements of the World Health Organization. In addition, the subpopulations monitoring of BCG Tokyo 172-1 vaccine were investigated on 109 lots and the results revealed that 65 lots (59.63%) contained less than 10% of BCG subtype II, whereas 44 lots (40.37%) contained more than 10% of BCG subtype II. These results compared with the BCG vaccine manufactured by Japan, which contained no more than 5% of BCG subtype II, and the vaccine manufactured by Taiwan, contained 40% of BCG subtype II. The correlation between the potency test and %BCG subtype II was analyzed, the results presented that the data has a very low value (r = -0.287) at 95% confidence level, revealing no correlation. Although, the trend varied inversely, there was no effect on the quality of the BCG vaccine because the testing results met the product specification. This study can be used as a guideline for further improving quality in the manufacturing of BCG vaccines used in the country.