Pneumonia is a life threatening public health concern particularly due to multidrug resistant (MDR) bacterial pathogens. The rising threat of these resistant bacterial strains has exacerbated the challenge of treating bacterial pneumonia, emphasizing the urgent need of alternative therapeutic strategies such as vaccine development by targeting combined localized MDR bacterial pneumonia pathogens. In this study, clinical samples of bacterial pneumonia pathogens were collected from tertiary care hospitals of Lahore, Punjab, Pakistan. Strains were isolated and characterized on biochemical and molecular basis. The localized vaccines, including inactivated whole-cell vaccines, bivalent vaccine (KP + SP), combined vaccine (SP + LPS) and lipopolysaccharide (LPS)-based vaccines by targeting the most dominant bacterial pathogens K. pneumoniae and S. pneumoniae were prepared. The experimental trial was conducted on 7th, 14th, 48th, 60th and 90th days interval. Mice were immunized and immune responses were assessed using complement fixation test (CFT). Mice were challenged with a lethal dose (LD50) of pathogenic strain of K. pneumoniae and S. pneumoniae. Then, survival rate of each group of mice were monitored over time. indicated that the mean antibody titers peaked on 48th day for all vaccine groups, followed by a decline by 90th day of post vaccination. Among all vaccine groups, the bivalent vaccine (KP + SP) exhibited the most significant results (p < 0.05), with 98-99% survival rate. It may be concluded from this study that bivalent vaccine (KP + SP) significantly enhanced the protective humoral immune response against MDR bacterial pneumonia pathogens. And, LPS have potential immunogenic components for future vaccine development.
Waqar et al. (Fri,) studied this question.