evidence: Fifteen months on from the administration of the first experimental COVID-19 vaccine doses to humans in March 2020, there is now a global race against the causative virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to deploy vaccines to control the pandemic1, with differing levels of vaccine rollout in different countries (Our World in Data). Despite authorization having been granted for multiple vaccines, as the ongoing global outbreaks demonstrate, the pandemic is far from over. Vaccination, in combination with non-pharmaceutical interventions, is the best way to control the pandemic. In this regard, we are fortunate that there is now a formidable toolkit of potential vaccines available: of the 322 candidate vaccines that have been proposed so far (July 2021), 99 are in clinical testing, 25 have reached phase III efficacy studies and 18 have received some form of approval for use. However, achieving global vaccine coverage remains a major hurdle; this is not just a matter of equity but is also an important part of the process to control the virus. SARS-CoV-2 continues to evolve under immune selective pressure, and while transmission levels remain high, there is an increased likelihood of vaccine escape variants evolving.