Seroprevalence of COVID-19 antibody among patients visiting a large clinic in Uttar Pradesh

Background: The study was conducted to determine the Coronavirus disease 2019 (COVID-19) antibody titre among patients who visited our clinic in Lucknow in order to find out the prevalence of sero positivity and to determine the association between COVID anti-body titre and positivity to different age groups, sex, and religions etc., if any.Methods: Secondary data analysis was conducted at Lucknow's Sitara polyclinic from patients’ data, who had attended the clinic between May 2021 and July 2021 and had universally undergone COVID antibody testing. COVID antibody (including IgG) levels in patients' blood were determined using Roche's commercial "Elecsys Anti-SARS-CoV2-cobas e411,601,602 system.by Roche which measure by Eclia (electro chemilusence immunoassay) quantitatively antibodies (including IgG). Patients with titres less than 1 u/ml were deemed seronegative for anti –SARS COVID-2, while those with titres greater than or equal to 1 u/ml were declared seropositive.Results: The overall rate of seropositivity was 84.8%. Around 84.5% males and 85.1% females were seropositive. Seropositivity was higher among 18 to 60 years of age. But there was no significant relation between mean age and seropositivity. Muslims had slightly higher seropositivity (86.0%) as compared to non-Muslims (84.5%). There was no significant difference between age and gender having positive COVID 19 antibody titres. Although the incidence of seropositivity was similar between Muslims and Non-Muslims, the antibody titres were significantly higher in Muslim patients.Conclusions: In this part of central eastern UP, incidence of seropositivity could already be as high as 85%, which is a pointer toward adequate herd immunity. COVID-19 does not differentiate on the basis of age, gender or religious affiliations. However, Muslims were found to have more antibody titres compared to non-Muslims, possibly related to life style, degree of exposure to COVID-19 virus and presence of inherent immunity.