PF4 and COVID-19: Additionally, SARS-CoV-2 infection in vaccinated patients with a history of VITT does not restimulate anti-PF4 antibodies (97); and second dosing with COVID-19 vaccines such as BNT162b2, mRNA-1273, and ChAdOx1 nCoV-19 in 26 patients with confirmed cases of VITT did not restimulate anti-PF4 antibodies as well (98).