Distribution of influenza A and B antibodies and correlation with ABO/Rh blood grouping

Abstract

Background: Influenza is a clinically-significant infection with significant number of globally reported annual deaths. The aim of this study was to study the distribution of influenza A and B antibodies in Najran, the Southwest region of Saudi Arabia, and to investigate the correlation between demographic characteristics and influenza virus antibody levels.Methods: Enzyme linked immunosorbent assay was used to detect antibody level of influenza A and B. The correlation with ABO/Rh blood groupings was also examined. The total number of participants was 252. Only twenty-four subjects received the flu vaccine.Results: It was found that 33.7% and 24.1% of unvaccinated subjects were IgG-positive for influenza A and B, respectively. Interestingly, the antibody levels of the unvaccinated participants were higher than the vaccinated group. A significant difference was found between unvaccinated participants with O+ and influenza A and B antibody levels (**p=0.0045). The antibody level was inversely correlated with age in influenza B IgG subjects but not influenza A IgG (r=-0.1379; R squared=0.01900; p=0.0375). Forty-three subjects (17%) were positive for antibodies of both influenza A and B.Conclusions: IgG antibody positivity is greater in cases of influenza type A compared to influenza B. A significant correlation was found in the unvaccinated group between influenza B IgG antibody levels and age, but not influenza A (*p=0.0375). More research is needed to investigate the role of O+ blood group in influenza infections.