Immunogenicity and safety of booster doses of CoronaVac vaccine in patients with autoimmune rheumatologic diseases patients

Abstract

Coronavirus 2019 disease (COVID-19) has proven to be the biggest health challenge since 2019. Vaccination is considered the most effective measure to prevent the spread, hospitalizations, and deaths related to COVID-19. However, more studies focused on more specific populations such as people suffering from autoimmune rheumatic diseases are still needed to make better use of the available vaccines. Our group previously showed that seroprotection and seroconversion rates, although moderate in this population, are lower than in controls. Thus, strategies to improve the vaccine response in this group, such as the administration of booster doses, are necessary. Our previous study reported that the humoral response after just one dose of CoronaVac vaccine in those previously infected with SARS-CoV-2 ('recovered'), reaches a similar plateau in both rheumatologic patients and controls. Furthermore, this response was far superior to the 2-dose vaccine response in patients and controls without prior SARS-CoV-2 infection ('naive'). These findings suggest that booster doses in naive rheumatologic patients would result in a significant increase in the capacity to provide better seroprotection. Therefore, the aim of this proposal is to evaluate the immunogenicity and safety of booster doses of the SARS-CoV-2 vaccine in patients with autoimmune rheumatic diseases. On September 19th, approximately 1600 participants (1200 patients and 400 controls) were included to receive the 3rd dose of CoronaVac and they were collected on the same day blood for detecting antibodies measured using immunoassay kits (Indirect ELISA, LIAISON® SARS-CoV-2 S1/S2 IgG, DiaSorin, Italy) and SARS-CoV-2 sVNT Kit (GenScript, Piscataway, NJ, USA). Booster dose response will be evaluated by collecting the blood of the same population in October, and those with inadequate humoral response will be referred to receive a 4a dose of a heterologous vaccine. The incidence of cases, hospitalizations, deaths from SARS-CoV-2, and adverse events after vaccination will be recorded throughout the study, as well as symptoms post the acute infection. (AU)