ERN ReCONNET Study on COVID-19 Vaccination in Rare and Complex Connective Tissue Disease (VACCINATE)

30 months, multicentre, prospective observational study on adult (\>18 years) patients with a diagnosis of rare and complex connective tissue diseases (rCTDs) who will be given the vaccine during the period from January 2021 and January 2022. Patients with the following diagnosis will be included: * antiphospholipid syndrome (APS), * Ehlers-Danlos syndrome (EDS), * idiopathic inflammatory myopathies (IIM), * IgG4-related disease (IgG4), * mixed connective tissue disease (MCTD), * relapsing polychondritis (RP), * Sjogren's syndrome (SS), * systemic lupus erythematosus (SLE), * systemic sclerosis (SSc) * undifferentiated connective tissue disease (UCTD)