Abstract
India is in the grip of a devastating second wave of Covid-19. Many experts believe new variants of concern (VOC) are behind this unprecedented surge. Some media reports are hinting toward higher risk of Covid infection following Covid vaccinations. 'Original antigenic sin,' in which a prior exposure to an antigen leads to an ineffective response to a related antigen, may offer one immunological explanation for this unusual association. There is an urgent need of undertaking a detailed study to prove/disprove this association.