Comparing response to SARS-CoV-2 mRNA vaccine doses for patients with RA and healthy controls.

This study evaluated immune responses after two doses of SARS-CoV-2 messenger RNA (mRNA) vaccines in patients with inflammatory joint diseases including rheumatoid arthritis (RA) compared to healthy controls (HCs). The data showed that patients with inflammatory joint diseases had similar responses to mRNA vaccines after 2 doses. 

Rheumatoid arthritis (RA) is an inflammatory disease in which a patient’s immune system attacks healthy cells (autoimmunity), resulting in painful, swollen joints. Patients with inflammatory diseases such as RA commonly need drugs that alter immune responses (immunomodulatory therapies). These aim to reduce autoimmunity and therefore pain and damage to the joints.

However, such therapies might cause patients to be at a higher risk of severe COVID-19 infections. Additionally, a functional immune system is needed for vaccines to produce an adequate antibody response. There is a need to explore the effectiveness of SARS-CoV-2 mRNA vaccines in patients with inflammatory joint diseases under immunomodulatory therapy.

This study included 99 patients with inflammatory joint diseases and 169 healthy control (HC) participants. Of the 99 patients, 53 patients had RA, while 46 patients had spondyloarthritis (SpA). Patients were treated with a conventional DMARD (csDMARD), a biological/targeted synthetic DMARD (b/ts DMARD), or combination therapy (a csDMARD and b/tsDMARD). All study participants received two doses of an mRNA vaccine. Antibody levels were evaluated 2 to 3 weeks after the first vaccination (dose), and 3 to 6 weeks after the second vaccination (dose).

After the first vaccine dose, 52.5% of patients with RA and 54.8% of patients with SpA developed antibodies in the blood, compared to 98% of HCs. After the second vaccine dose, 100% of patients and HCs had antibodies.

Patients on combination therapy had lower antibody levels after the first vaccine dose compared to those that received csDMARD or b/tsDMARD only. There was no change in disease activity after vaccinations that required treatment changes in patients with inflammatory conditions. 

The study showed that two doses of SARS-CoV-2 mRNA vaccine are required to produce adequate levels of antibodies in patients with inflammatory joint diseases under DMARD therapy.

The study did not determine whether the antibody quantities were protective due to neutralizing functions. The number of patients included was low.