RESUMEN
AIM: To detect the immunoglobulin M memory B cell population response following vaccination with the 23-valent pneumococcal polysaccharide vaccine and determine its relation to frailty indices, nutritional status, and serum zinc levels. METHODS: A cross-sectional study was carried out in the outpatient geriatric clinic, Ain Shams University Hospital. It included 80 community-dwelling elderly, 32 male and 48 female. Each participant underwent vaccination with the 23-valent pneumococcal polysaccharide vaccine, comprehensive geriatric assessment, nutritional assessment with the DETERMINE check list, frailty indices assessment, and serum zinc level measurement. The percentage of immunoglobulin M memory B cells was evaluated before and 4 weeks after vaccination. Immune response was calculated as the difference between cell percentage before and after vaccination. RESULTS: Before the vaccination, the immunoglobulin M memory B cell percentage was significantly lower among those eating fewer than two meals a day and taking three or more drugs a day; after vaccination significance was observed among those with tooth or mouth problems that make eating difficult. Immune response was significantly lower among those with tooth or mouth problems (P < 0.001), weight loss (P < 0.001), shrinking (P = 0.001), poor endurance (P = 0.04), multiple comorbidities (P = 0.013), and cognitive impairment (P = 0.001). Participants with immune response ≥10% showed significantly higher serum zinc levels compared to those with immune response <10% of increase in cell percentage. CONCLUSION: Poor nutritional status, frailty and a lower zinc level impair the immunological response of elderly individuals.