Waning of antibody response among vaccinees who received two doses of covishield vaccine

• Published in: Journal of global infectious diseases Vol. 15; no. 1; pp. 19 - 22
• Main Authors: Haritay, Shivani, Patil, Rithia, Maldar, Arif, Kumar, Anil, Reddy, Vikrama, Oswal, Deshna, Tahashildar, Masood, Kolakar, Akshay, Kabbur, Satish, Prasad, Jang, Shivaswamy, M, Paranjape, Ramesh, Angolkar, Mubashir
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer India Pvt. Ltd 01.01.2023; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Wolters Kluwer - Medknow; Wolters Kluwer Medknow Publications
• Subjects: Antibodies; antibody waning; booster dose; COVID-19; covid-19 vaccine; COVID-19 vaccines; Cross-sectional studies; elderly population; Health aspects; immunoglobulin g antibodies; Immunoglobulins; Older people; Original; sars-cov-2; Severe acute respiratory syndrome coronavirus 2; Vaccines; India; elderly population; COVID-19 vaccine; SARS-CoV-2; immunoglobulin G antibodies; Antibody waning; booster dose
• ISSN: 0974-777X; 0974-8245
• DOI: 10.4103/jgid.jgid_128_22

Introduction: There are limited data available on the long-term presence of SARS-CoV-2-specific binding antibodies and neutralizing antibodies in circulation among the elderly population. This study aims to examine levels of anti-SARS-CoV-2 antibodies in vaccines who have completed at least 6 months since the second vaccine dose. A cross-sectional study was conducted from November 2021 to January 2022 among 199 vaccines aged 60 years and above residing in Belagavi city, who received two doses of the Covishield vaccine. Methods: Antibody response to SARS-COV-2 virus whole cell antigen was measured by a kit COVID KAWACH IgG Micro LISA (J Mitra and Company, India) in 199 participants who had completed at least 6 months after receiving the second dose of Covishield vaccine. The antibody response was measured as a ratio of optical density (OD) in the participant's sample to the mean OD in negative control test by normal (T/N). Independent Kruskal-Wallis test was applied to test the difference between the T/N ratio by months of vaccination since the second dose and by the age group strata. Results: The median T/N values among participants who completed 6, 7, 8, and 9 months since the second vaccine dose were 14.17, 10.46, 7.93, and 5.11, respectively, and this decline in T/N values was statistically significant. Antibody response values showed a decline with increasing age for participants in the age strata 60-69, 70-79, and 80 and above, respectively. Conclusions: A significant decline was observed in antibody response over 9 months supporting the administration of booster dose of vaccine.