There have been limited studies comparing Chinese and American news media in their descriptions of vaccines, especially their use of metaphors in the context of COVID-19. Hence, this paper employs a corpus-assisted critical approach to examine the metaphors used in constructing crisis discourses relating to vaccines in Chinese and American newspapers. The study reveals four conceptual metaphors: WEAPON, MACHINE, TRAVELLER, and CONTEST . The usage of these metaphors is intertwined with wider discursive contexts, which are shaped by the two countries' distinct journalistic and geopolitical/sociocultural contexts. These have resulted in the adoption of different strategies for handling the COVID-19 crisis, reflecting the ideologies of collectivism in China and capitalism in America. The study highlights the significance of metaphors in shaping the ideologies of governments and/or the public towards vaccines through news media. Additionally, this paper provides a useful framework for comparing metaphor usage in two large corpora using Wmatrix.