As COVID-19 ravaged the world, its management was undercut by conspiracy perceptions that construct different versions of reality about the pandemic. This has hugely attracted scholarly attention in several fields but discourse analysis. This study was thus motivated to investigate the discursive constructions of conspiracies, the interpretive repertoires, expressed feelings, and enacted social actions. Data were sourced from posts and comments on Coronavirus and the vaccines on Twitter, Facebook, and Nairaland social media platforms, and subjected to discourse analysis. Three conspiracy perceptions were identified: COVID-19 as fraud, COVID-19 vaccine (COVAX) as a depopulation plan, and COVAX as associated with the 5G network. These were constructed in COVAX conspiracy discourse through these interpretive repertoires: reference, evaluative devices, time clauses, and intensifiers under lexicogrammar; and inclusive/exclusive distinctions, argumentation, historical allusion, rhetorical question, and narratorial trope under rhetorical strategies. These enacted the social actions of disputing, alleging, justifying, denouncing, and prognosticating, which worked up the negative emotions of dissatisfaction, apprehension, anger, insecurity, and disinclination expressed in terse textual voices that suppress the official COVAX narrative and endorse the alternative views.