Evaluation of patients with antiphospholipid syndrome subsequently COVID-19 vaccinations: A retrospective cohort study.

The aim of this study is to evaluate development of side effects, thrombotic or obstetric complications in our antiphospholipid syndrome (APS) patient group, after vaccination against coronavirus disease 2019 (COVID-19). A cohort was formed from patients who have previously been followed up with a diagnosis of APS. The patients of the cohort were evaluated retrospectively to find out if they were vaccinated with CoronaVac and/or BNT162b2 vaccines which are being used in our country. To evaluate the side effects seen after the vaccination, the information was collected by the patients in their outpatient appointments or making a phone call. Thirty-five APS patients who had received at least 1 dose of any of the COVID-19 vaccines were included in the study. Median (min-max) number of vaccine doses per patient was 2 (1-3). Eleven patients had a booster dose after primary vaccination. Twenty patients were ever vaccinated with BNT162b2 and 18 with CoronaVac. Among BNT162b2 recipients, 9 (45.0%) and among CoronaVac recipients 15 (42.9%) reported an adverse event after a vaccine administration. The most common adverse events were myalgia and malaise after any dose of both vaccines. No vaccine-related new thrombotic events or APS flares were observed. Our results were comparable with those reported in the literature. Comprehensive large-scale studies are needed for more accurate results on the evaluation of side effects after COVID-19 vaccination in APS patients.