Antibody response to the COVID-19 ChAdOx1nCov-19 and BNT162b vaccines after temporary suspension of DMARD therapy in immune-mediated inflammatory disease: an extension study (RESCUE 2).

The persistence of immunogenicity in patients with immune-mediated inflammatory diseases (IMID) on disease-modifying antirheumatic therapy (DMARD) has been less well studied. This extension study evaluates the SARS-CoV2 antibody decay kinetics 6 months following two doses of ChAdO1nCov-19 (AZ) and BNT162b (Pfizer) and subsequent response following an mRNA booster. RESULTS: 175 participants were included. Six months after initial AZ vaccination, 87.5%, 85.4% and 79.2% (p=0.756) in the withhold, continue and control groups remained seropositive compared with 91.4%, 100% and 100% (p=0.226), respectively, in the Pfizer group. Both vaccine groups developed robust humoral immune responses following a booster with seroconversion rates being 100% for all three intervention categories. The mean SARS-CoV-2 antibody levels were significantly lower in the targeted synthetic DMARD (tsDMARD) group that continued therapy compared with the control (2.2 vs 4.8 U/mL, p=0.010). The mean time interval until loss of protective antibodies in the IMID group was 61 days for the AZ and 137.5 days for the Pfizer vaccine. Within each DMARD class the interval until loss of protective antibody titres in the csDMARD, bDMARD and tsDMARD groups were 68.3, 71.8 and 64.0 days in the AZ group and 185.5, 137.5 and 116.0 days in the Pfizer group, respectively. CONCLUSION: Antibody persistence was longer in the Pfizer group due to a higher peak antibody level following second vaccination with levels of protection in IMID on DMARD therapy similar to controls except in those on tsDMARDs where it was lower. A third mRNA vaccine booster can restore immunity in all groups.

Antibody response to the COVID-19 ChAdOx1nCov-19 and BNT162b vaccines after temporary suspension of DMARD therapy in immune-mediated inflammatory disease (RESCUE).

OBJECTIVE: To assess the antibody response to disease-modifying antirheumatic drug (DMARD) therapy after the first and second dose of the ChAdOx1nCov-19 (AstraZeneca (AZ)) and BNT162b (Pfizer) vaccines in patients with immune-mediated inflammatory disease (IMID) compared with controls and if withholding therapy following the first vaccination dose has any effect on seroconversion and SARS-CoV-2 antibody (Ab) levels. METHODS: A multicentre three-arm randomised controlled trial compared the immunogenicity of the Pfizer and AZ vaccines in adult patients on conventional synthetic (csDMARD), biologic (bDMARD) or targeted synthetic (tsDMARD) therapy for IMID (n=181) with a control group (n=59). Patients were randomised to continue or withhold DMARD therapy for 1-2 weeks post first dose vaccination only. Serum SARS-CoV-2 IgG detection (IgG ≥1.0 U/mL) and titres against the S1/S2 proteins were measured at baseline, 3-4 weeks post first vaccination and 4 weeks post second vaccination. RESULTS: AZ vaccination was given to 47.5%, 41.5% and 52.5% in the continue, withhold and control groups, respectively while Pfizer vaccination was given to 52.5%, 58.5% and 47.5% among the continue, withhold and control groups, respectively. Seroconversion rates following the first dose in the AZ and Pfizer groups were only 27.3% vs 79.2% (p=0.000) and 64.58% vs 100% (p=0.000), respectively in the IMID groups who continued therapy compared with the AZ and Pfizer controls, respectively. Withholding DMARD therapy following the first vaccination dose resulted in higher seroconversion to 67.7% and 84.1% in the AZ and Pfizer groups, respectively. Following the second AZ and Pfizer vaccinations when all DMARDs were continued, despite a slightly lower seroconversion rate (83.7% vs 100%, p=0.000 and 95.9% vs 100%, p=0.413), respectively, the mean SARS-CoV2 IgG Ab titres were not significantly different in the csDMARD and bDMARD groups compared with the controls regardless of hold while it was significantly lower in patients taking tsDMARD (12.88 vs 79.49 U/mL, p=0.000). CONCLUSIONS: Following the first vaccination dose, antibody responses were lower in IMID on DMARD therapy, however the final responses were excellent regardless of hold with the exception of the tsDMARD group where withholding therapy is recommended. At least 2 vaccinations are therefore recommended preferably with an messenger RNA vaccine. TRIAL REGISTRATION NUMBER: ANZCTR: 12621000661875.