Do you recommend COVID vaccination in patients with antiphospholipid antibody positivity or other prothrombotic states not on anti-coagulation?  

There are hypothetical reasons that the COVID-19 vaccine might increase thrombophilia in individuals with APS/APLAs. However, the only controlled study I could find, Absence of hypercoagulability after nCoV-19 vaccination: An observational pilot study by Campello et al., PMID 34246010 did not show a...