This rapid research brief responds to the question - what are the most promising vaccines in development globally and nationally, and what are their mechanisms of action, their stage of development and their strengths and limitations?

Key findings:

• There are currently 10 vaccine candidates for COVID-19 in clinical trials. Many of these vaccines are being developed using new platforms and technologies.
• It is likely that several vaccine candidates will generate initial human safety and efficacy results in 2020. These results could inform the initial use of a limited number of vaccine doses under emergency or compassionate protocols for at-risk populations including frontline health workers, the elderly and those with significant co-morbidities.
• It is too early to select the ‘most promising’ vaccine candidate as we do not yet know their safety or efficacy, or our capability to manufacture them at large scale under Good Manufacturing Practice conditions. Furthermore, it is not a given that vaccines licensed first will be the most effective.