covid-19 vaccine (chadox1-s [recombinant]) (AstraZeneca)

ChAdOx1 CoV-19 vaccine (recombinant), also known as AZD1222 or Vaxzevria, is a replication-deficient chimpanzee adenovirus-vectored vaccine developed by the University of Oxford, Vaccitech, and AstraZeneca for the prevention of COVID-19. The vaccine utilizes the ChAdOx1 viral vector to deliver the genetic sequence encoding the full-length, codon-optimized spike (S) glycoprotein of the SARS-CoV-2 virus. Upon intramuscular administration, host cells express the spike protein, triggering a robust humoral and cellular immune response, including the production of neutralizing antibodies and T-cell activation. Although highly effective in reducing COVID-19 severity and hospitalization, the vaccine has been associated with a very rare but serious prothrombotic adverse event known as vaccine-induced immune thrombotic thrombocytopenia (VITT), driven by the formation of pathogenic antibodies against platelet factor 4 (PF4). In March 2024, AstraZeneca voluntarily withdrew the marketing authorization for Vaxzevria in the European Union for commercial reasons.

Brand names

CovishieldVaxzevria

Other names

AstraZeneca COVID-19 VaccineCOVID-19 Vaccine AstraZenecaCOVID19 Vaccine AstraZenecaCOVID 19 Vaccine AstraZenecaOxford-AstraZeneca COVID-19 vaccineOxford-AstraZeneca vaccineOxford vaccine