Long-term antibody responses to COVAXIN and COVISHIELD vaccines in rheumatoid arthritis patients and healthy control population - A cross-sectional study.

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation and damage in the joints. It often requires treatment with disease-modifying antirheumatic drugs (DMARDs) to manage symptoms and prevent progression. The study investigates the long-term antibody responses to COVAXIN and COVISHIELD vaccines in RA patients.

Methodology: This cross-sectional study (IEC approval no: AlIMS/BBN/IEC/AUG/2021/60-R dated Sept 05, 2022, and Ref No: 799/U/IEC/ESICMC/F490/09/2022 dated Oct 31, 2022) enrolled 103 diagnosed RA patients receiving DMARDs and 183 healthy controls. The participants who completed 1 year after the second dose of vaccination were included, and detailed information on demographic, medical, and vaccination were collected. Laboratory investigations included complete blood count, inflammatory markers, and antispike antibody levels. Statistical analyses assessed differences between COVAXIN and COVISHIELD subgroups, considering DMARDs usage and disease duration.

Results: Among RA patients, both COVAXIN and COVISHIELD groups exhibited low disease activity. No significant ( > 0.05) differences were found in IL-6, CRP, or antispike antibody levels between COVAXIN and COVISHIELD subgroups in RA patients and healthy controls. Notably, 89% of female RA patients received COVISHIELD. Co-morbidities, including hypothyroidism (44%), were prevalent in COVISHIELD-received RA patients. Antibody concentration varied significantly among DMARDs usage groups in COVAXIN-vaccinated RA patients, with a notable difference between three-drug and HCQ-alone regimens. However, no such difference was observed in the COVISHIELD group. Disease duration did not significantly impact antispike antibody concentration in either of the vaccination group.

Conclusion: RA patients had a decreased antibody response, 1 year after receiving the second dose of the COVID-19 vaccine. Nonetheless, there was no discernible difference in the antispike antibody concentration between the COVISHIELD and COVAXIN vaccination groups. Additionally, immunosuppressive medications significantly impact serological responses to these vaccines.