Study participants
hypersensitivity, systemic disorder, allergic reactions
HYPERSENSITIVITY, ALLERGIC REACTION
The study participants were healthy adults aged ≥ 18 years who gave written informed consent and who had completed primary COVID-19 immunization schedule of two doses with either ChAdOx1 nCoV-19 or BBV152 at least 6 months ago. Participants with a history of laboratory confirmed COVID-19, history of allergic reactions after previous vaccinations, hypersensitivity to any component of study vaccines, any condition with impaired/altered function of immune system, any clinically significant systemic disorder were excluded. Clinically well-controlled comorbidities were allowed.