Objective To assess antibody response to inactivated COVID-19 vaccine in patients with immune-mediated diseases (IMD) among hospital workers and people aged 65 and older. Methods In this cross-sectional study, we studied 82 hospital workers with IMD (mean age: 42.2 ± 10.0 years) and 300 (mean age: 41.7 ± 9.9 years) controls. Among + 65 aged population, we studied 22 (mean age: 71.4 ± 4.5 years) patients and 47 controls (mean age: 70.9 ± 4.8 years). All study subjects had a negative history for COVID-19. Sera were obtained after at least 21 days following the second vaccination. Anti-spike IgG antibody titers were measured quantitatively using a commercially available immunoassay method. Results Patients with IMD were significantly less likely to have detectable antibodies than healthy controls both among the hospital workers (92.7% vs 99.7%, p < 0.001) and elderly population (77.3% vs 97.9%, p = 0.011). Among patients with IMD, those using immunosuppressive or immune-modulating drugs (64/75, 85.3%) were significantly less likely to have detectable antibodies compared to those off treatment (29/29, 100%) ( p = 0.029). Additionally, a negative association between age and the antibody titer categories among patients ( r = − 0.352; p < 0.001) and controls ( r = − 0.258; p < 0.001) were demonstrated. Conclusions Among hospital workers, the vast majority of patients with IMD and immunocompetent controls developed a significant humoral response following the administration of the second dose of inactivated COVID-19 vaccine. This was also true for the elderly population, albeit with lower antibody titers. Immunosuppressive use, particularly rituximab significantly reduced antibody titers. Antibody titers were significantly lower among those aged ≥ 60 years both in patient and control populations. Whether these individuals should get a booster dose warrants further studies. Supplementary Information The online version contains supplementary material available at 10.1007/s00296-021-04910-7.

Most of the published data relate to classical forms of rheumatic diseases (RD) and information on rare inflammatory disorders such as Behçet’s syndrome (BS) and familial Mediterranean fever (FMF) is limited. We studied the frequency of side effects and disease flares after COVID-19 vaccination with either Pfizer/BioNTech or Sinovac/CoronaVac in 256 patients with BS, 247 with FMF, and 601 with RD. Telephone interviews were conducted using a questionnaire survey in a cross-sectional design in patients with BS, FMF, and RD followed by a single university hospital. Study participants were vaccinated either with CoronaVac (BS:109, FMF: 90, and RD: 343,) or BioNTech (BS: 147, FMF: 157 and RD: 258). The majority have received double dose (BS: 94.9%, FMF 92.3% and RD: 86.2%). BioNTech ensured a significantly better efficacy than CoronaVac against COVID-19 in all patient groups (BS: 1.4% vs 10.1%; FMF: 3.2% vs 12.2%, RD:2.7% vs 6.4%). Those with at least one adverse event (AE) were significantly more frequent among those vaccinated with BioNTech than those with CoronaVac (BS: 86.4% vs 45%; FMF: 83.4% vs 53.3%; and RD: 83.3% vs 45.5%). The majority of AEs were mild to moderate and transient and this was true for either vaccine. There were also AEs that required medical attention in all study groups following CoronaVac (BS: 5.5%, FMF: 3.3%, and RD:2.9%) or BioNTech (BS: 5.4%, FMF: 1.9%, and RD: 4.7%). The main causes for medical assistance were disease flare and cardiovascular events. Patients with BS (16.0%) and FMF (17.4%) were found to flare significantly more frequently when compared to those with RD (6.0%) ( p < 0.001). This was true for either vaccine. BS patients reported mainly skin-mucosa lesions; there were however, 11 (4.3%) who developed major organ attack such as uveitis, thrombosis or stroke. Flare in FMF patients were associated mainly with acute serositis with or without fever. Arthralgia/arthritis or inflammatory back pain were observed mainly in the RD group. Our study demonstrates that BS and FMF patients vaccinated with either CoronaVac or BioNTech demonstrated similar AE profile and frequency compared to RD patients. AEs that required physician consultation or hospitalization occurred in all study groups after either CoronaVac or BioNTech. Increased frequency of flares in BS and FMF compared to that seen in RD might reflect defects in innate immunity and deserves further investigation. Caution should be required when monitoring these patients after vaccination.

Initial case series of small number of patients at the beginning of the pandemic reported a rather guarded prognosis for Behçet's syndrome (BS) patients infected with SARS-CoV-2. In this prospective study, we describe the incidence, clinical characteristics, disease course, management, and outcome in a large cohort of BS patients with laboratory-confirmed infection of SARS-CoV-2. We defined a cohort of 1047 registered BS patients who were aged between 16 and 60 years and seen routinely before the pandemic at the multidisciplinary outpatient clinic. We followed prospectively this cohort from beginning of April 2020 until the end of April 2021. During 13 months of follow-up, of the 1047 (599 M/448 F) patients, 592 (56.5%) were tested for SARS-CoV-2 PCR at least once and 215 (20.5%; 95% CI 0.18-0.23) were tested positive. We observed 2 peaks which took place in December 2020 and April 2021. Of the 215 PCR positive patients, complete information was available in 214. Of these 214, 14 (6.5%) were asymptomatic for COVID-19. In the remaining, the most common symptoms were anosmia, fatigue, fever, arthralgia, and headache. A total of 40 (18.7%) had lung involvement, 25 (11.7%) were hospitalized, 1 was admitted to the intensive care unit while none died. Favipiravir was the most prescribed drug (74.3%), followed by colchicine (40.2%), and hydroxychloroquine (20.1%) in the treatment of COVID-19. After COVID-19, 5 patients (2.3%) were given supplemental O 2 and 31 (14.5%) antiaggregant or anticoagulants. During COVID-19, of the 214 PCR positive patients, 116 (54.2%) decreased the dose of their immunosuppressives or stopped taking completely; 36 (16.8%) experienced a BS flare which was mostly oral ulcers (10.3%). None of the patients reported a thrombotic event. A total of 93 (43.5%) patients reported BS flares after a median 45 days of COVID-19 infection and this was found to be significantly associated with immunosuppressive drug discontinuation. Multiple regression analysis adjusted for age and gender indicated that smoking and using interferon-alpha decreased the likelihood of getting COVID-19. The incidence and severity of COVID-19 did not differ between those who were using colchicine or not. The cumulative incidence of COVID-19 in this prospectively followed cohort of BS patients was almost two folds of that estimated for the general population living in Istanbul, Turkey, however, the clinical outcome of COVID-19 was not severe and there was no mortality. The protective effect of smoking and interferon deserves further investigation. On the other hand, colchicine did not have any positive or negative effect against COVID-19. Significant number of patients flared after COVID-19, however, this was significantly associated with immunosuppressive discontinuation during the infection. Contrary to our previous observations, COVID-19 did not seem to exacerbate thrombotic events during or after the infection.