International Journal of Research in Medical Sciences | December 2022 | Vol 10 | Issue 12 Page 1 International Journal of Research in Medical Sciences Hakami AR et al. Int J Res Med Sci. 2022 Dec;10(12):xxx-xxx www.msjonline.org pISSN 2320-6071 | eISSN 2320-6012 Original Research Article Distribution of influenza A and B antibodies and correlation with ABO/Rh blood grouping Abdulrahim R. Hakami 1 , Abdullah J. Alshahrani 2 , Osama A. Alshehri 3 , Ahmed Saif 4 , Ahmad A. Alshehri 4 * INTRODUCTION Influenza virus is a seasonal human pathogen that causes severe symptoms globally. It is also an enveloped orthomyxovirus that possess segmented negative stranded RNA genome. 1 Influenza is a contagious respiratory condition occurring mostly in the winter season and is associated with fever, cough, sore throat, fatigue, and runny and/or stuffy nose. Some infected people develop complications, such as pneumonia, which can be life- threatening and result in death if not adequately treated. 2 Influenza A virus strains including H1N1 and H3N2 are responsible for most of the severe cases and deaths worldwide. 3 It is estimated that seasonal influenza infects up to 15% of the global population and causes nearly half a million deaths. 4 1 Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia 2 Department of Public Health, General Directorate of Health Affairs in Asir Region, Abha, Saudi Arabia 3 Public Health Laboratory, Public Health Authority, Riyadh, Saudi Arabia 4 Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Najran University, Najran, Saudi Arabia Received: 14 October 2022 Accepted: 29 October 2022 *Correspondence: Dr. Ahmad A. Alshehri, E-mail: aaalshehri@nu.edu.sa Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 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. Keywords: Anti-influenza antibodies, Blood groups, Flu vaccine DOI: https://dx.doi.org/10.18203/2320-6012.ijrms20222965