Background: Currently there is little information on the efficacy and safety of SARS-CoV-2 vaccination in patients with immune-mediated diseases and/or under immunosuppressive treatment in our country, where different types of vaccines and mix regimens are used. For this reason, the Argentine Society of Rheumatology (SAR) with the Argentine Society of Psoriasis (SOARPSO) set out to develop a national register of patients with rheumatic and immune-mediated inflammatory diseases (IMIDs) who have received a SARS-CoV-2 vaccine in order to assess their efficacy and safety in this population.

Objectives: To assess SARS-CoV-2 vaccine efficacy and safety in patients with rheumatic and IMIDs.

Methods: SAR-CoVAC is a national, multicenter and observational registry. Adult patients with a diagnosis of rheumatic or IMIDs who have been vaccinated for SARS-CoV-2 were consecutively included between June 1st and September 17th, 2021. Sociodemographic data, comorbidities, underlying rheumatic or IMIDs, treatments received and their modification prior to vaccination and history of SARS-CoV-2 infection were recorded. In addition, the date and place of vaccination, type of vaccine applied, scheme and indication will be registered. Finally, adverse events (AE), as well as SARS-CoV-2 infection after the application of the vaccine were documented

Results: A total of 1234 patients were included, 79% were female, with a mean age of 57.8 (SD 14.1) years. The most frequent diseases were rheumatoid arthritis (41.2%), osteoarthritis (14.5%), psoriasis (12.7%) and spondyloarthritis (12.3%). Most of them were in remission (28.5%) and low disease activity (41.4%). At the time of vaccination, 21% were receiving glucocorticoid treatment, 35.7% methotrexate, 29.7% biological (b) Disease Modifying Anti-Rheumatic Drugs (DMARDs) and 5.4% JAK inhibitors. Before vaccine application 16.9% had had a SARS-CoV-2 infection.

Regarding the first dose of the vaccine, the most of the patients (51.1%) received Gam-COVID-Vac, followed by ChAdOx1 nCoV-19 (32.8%) and BBIBP-CorV (14.5%). In a lesser proportion, BNT162b2 (0.6%), Ad26.COV2.S (0.2%) and CoronaVac (0.2%) vaccines were used. Almost half of them (48.8%) completed the scheme, 12.5% were mix regimenes, the most frequent being Gam-COVID-Vac / mRNA-1273. The median time between doses was 51days (IQR 53).

More than a quarter (25.9%) of the patients reported at least one AE after the first dose and 15.9% after the second. The flu-like syndrome and local hypersensitivity were the most frequent manifestations. There was one case of mild anaphylaxis. No patient was hospitalized. Altogether, the incidence of AE was 246.5 events/1000 doses. BBIBP-CorV presented significantly lower incidence of AE in comparison with the other types of vaccines. (118.5 events/1000 doses, p<0.002 in all cases)

Regarding efficacy, 63 events of SARS-CoV-2 infection were reported after vaccination, 19% occurred before 14 days post-vaccination, 57.1% after the first dose (>14 days) and 23.8% after the second. In most cases (85.9%) the infection was asymptomatic or had an outpatient course and 2 died due to COVID-19.

Conclusion: In this national cohort of patients with rheumatic and IMIDs vaccinated for SARS-CoV-2, the most widely used vaccines were Gam-COVID-Vac and ChAdOx1 nCoV-19, approximately half completed the schedule and in most cases homologously. A quarter of the patients presented some AE, while 5.1% presented SARS-CoV-2 infection after vaccination, in most cases mild.

Disclosure of Interests: None declared