Immunogenicity, safety and reactogenicity of a heterogeneous booster following the CoronaVac inactivated SARS-CoV-2 vaccine in patients with SLE: a case series.

Since the COVID-19 pandemic, CoronaVac, an inactivated SARS-CoV-2 vaccine, has been widely deployed in several countries for emergency use. However, the immunogenicity of the inactivated vaccine was relatively lower when compared to other vaccine types and was even more attenuated in autoimmune patients with rheumatic disease. A third-dose SARS-CoV-2 vaccination in immunosuppressed population is recommended in order to improve immune response. However, the data were limited to those initially received mRNA or viral vector SARS-CoV-2 vaccine. Thus, we aimed to describe the safety, reactogenicity and immunogenicity of patients with systemic lupus erythematosus (SLE) who received a heterogenous booster SARS-CoV-2 vaccine following the initial CoronaVac inactivated vaccine series. Our findings support that the third booster dose of mRNA or viral vector vaccine following the inactivated vaccine is well tolerated and elicited a substantial humoral and cellular immune response in inactive patients with SLE having maintenance immunosuppressive therapy without interruption of immunosuppressive medications.