Anti- SARS-CoV-2 IgG and IgM Levels in Iraqi General Population

Abstract

Background: Acquired immunity plays an important role in the prevention of viral infec-tions. SARS-CoV-2 is an infection that leads to a pandemic. The development of specific anti-SARS-CoV-2 antibodies may play a vital role in disease prevention and control. Thus IgG antibody screening in the general population provides information on the immunological status of the community Aim: To clarify the SARS-CoV-2 immune status in the general population. Methods: A cross-sectional study was conducted in Kirkuk province during the period from 15 May 2022 to 11 September 2022. The samples were collected from voluntary subjects and informed con-sent was taken from each participant before their enrolment in the study. SARS-CoV-2 IgG, SARS-CoV-2 IgM, 25-OH Vitamin D, Vitamin B12, and Folate were determined using the Electrochemi-luminescence Immunoassay (eCLIA) technique with the instrument NIPIGON-Robot R1Automated ECL Analyzer (Canada). Results: The overall IgG mean concentration was 37.75 ± 23.18 COI, with a median of 39.99 COI and a range of 0.25 - 87.23 COI. Additionally, 93% of tested samples were with concentrations of more than 1 COI. The highest frequency (18.2%) was for the IgG concentration of 51 to 60 COI, while the lowest frequency (1.3%) was for the concentration of 81 - 90 COI. The IgG was signifi-cantly higher (P = 0.046) in males (39.87 ± 24.04 COI) than that in females (35.12 ± 21.89 COI). The IgM overall concentration was 0.569 ± 0.456 COI, with a median of 0.489 COI and a range of 0.17 - 6.40 COI. The mean serum level of folic acid concentration was 9.03 ± 5.72 ng/ml, with a median of 7.476 ng/ml and a range of 0.60 - 20.00 ng/ml. The mean serum concentration of vitamin B12 was 462.65 ± 349.18 pg/ml, with a median of 353 pg/ml and a range of 13.05 - 2000 pg/ml. The mean serum concentration of vitamin D was 18.29 ± 18.42 ng/ml with a median of 12.44 ng/ml and a range of 3 - 100 ng/ml. IgG and IgM serum levels did not show a significant correlation with serum levels of folic acid, vitamin D, and vitamin B12. However, there was a significant correlation between folic acid and vitamin D (r = 0.197; P = 0.012); vitamin B12 and vitamin D (r = 0.253, P = 0.001). While there was a non-significant correlation between folic acid and vitamin D serum levels (r = 0.129, P = 0.10). Conclusion: General population IgG antibody concentration reflects a high rate of herd immunity. Folic acid was with a mean value of about half of the upper normal limit and only 17.7% were with low values. Vitamin B12, only 6.3% of the population had values lower than normal. However, the range of vitamin B12 was wide. While vitamin D values were lower than the normal limit at 82.6%. However, a large scale well designed was warranted to evaluate COVID-19 national immune re-sponse.