ABSTRACT
Objectives: Patients with immune-mediated diseases achieve lower seroconversion rates to COVID19 vaccines compared to healthy controls. The aim of this study was to assess the SARS-CoV-2-specific humoral and T-cell responses after a two-dose regimen of SARS-CoV-2 vaccine in patients with rheumatoid arthritis (RA). Method(s): Observational study. Patients with RA, >=18 years of age, who were vaccinated according to the Argentine National Health Ministry's vaccination strategy were included. Anti-SARS-CoV-2 IgG antibodies, neutralizing activity and specific T-cell responses were assessed after the first and second doses. Result(s): A total of 120 RA patients were included. Mostly, homologous regimens were used, including Gam-COVID-Vac (27.5%), ChAdOx1 (24.2%), BBIBP-CorV (22.5%) and BNT162b2 (0.8%), while the most frequent combination of vaccines was Gam-COVID-Vac/mRNA-1273 (21.7%). After the second dose 81.7% presented anti-SARS-CoV-2 antibodies, 70.0% neutralizing activity and 65.3% specific T-cell response. The use of BBIBP-CorV, treatment with abatacept (ABA) and rituximab (RTX) were associated with undetectable antibodies and no neutralizing activity after two doses of vaccine. BBIBP-CorV was also associated with the absence of T-cell response. The total incidence of adverse events was 357.1 events/1000 doses: significantly lower with BBIBP-CorV (166.7 events/1000 doses, p alpha 0.02). Conclusion(s): In this cohort of patients with RA who received 2 doses of COVID-19 vaccine, according to the Argentine strategic vaccination planwhich included homologous and heterologous regimens, two of ten did not develop IgG anti-SARS-CoV-2, 70% presented neutralizing activity and 65% specific T-cell response. The use of BBIBP-CorV was associated with deficient humoral and cellular response, while treatment with ABA and RTXaffected the development of IgG anti-SARS-CoV-2 and neutralizing activity.