If 2020 was the year of “mask diplomacy”, as countries raced to tackle the spread of the SARS-CoV-2 virus and acquire the necessary protective gear and equipment, 2021 is likely to be remembered as the year of “vaccine diplomacy”. Growing competition between states to secure the necessary quantities of vaccines to inoculate their population has already become an established feature of the post-COVID international system and such trends are only likely to increase in the near future.