COVID-19 hit the world affecting millions of people’s life, as well as increasing international demands for protective vaccine. Regarded as the source of the coronavirus, China began its “vaccine diplomacy” after being the first country to overcome the pandemic around early 2020. Through assisting other developing countries that are struggling with coronavirus cases, China donated and sold large number of vaccine doses abroad. Such exports of Chinese vaccine in the global health battle have attracted substantial global attention. This paper aims to take a close look at the “vaccine diplomacy” conducted by China in conjunction with a comprehensive case study of Chinese political allies, Iran and Uganda. In particular, we analyzed the economic and political factors which are associated with Chinese vaccine exports, along with the corresponding health and economic impacts. We used the OLS regression model to test the correlated relationship between the total vaccine delivered with transactions and donations divided and bilateral economic and political relationships. The results show that countries with stronger economic ties with China would import more vaccines from China either through donations or transactions. Positive political relations, such as donations to China during January to February in 2020, also work as an essential factor for whether receive Chinese vaccine or not. Yet the findings are not significant enough for other demand and control variables.