Clin Exp Immunol. 2020 Sep 15. doi: 10.1111/cei.13517. Online ahead of print.
Since the emergence of COVID-19, caused by the SARS-CoV-2 virus, at the end of 2019 there has been an explosion of vaccine development. By the 1st September 2020, a staggering number of vaccines (over 200) had started pre-clinical development of which 39 had entered clinical trials, including some approaches that have not previously been licensed for human vaccines. Vaccines have been widely considered as part of the exit strategy to enable the return to previous patterns of working, schooling and socialising. Importantly, to effectively control the COVID-19 pandemic, production needs to be scaled up from a small number of pre-clinical doses to enough filled vials to immunise the world's population, which requires close engagement with manufacturers and regulators. It will require a global effort to control the virus, necessitating equitable access for all countries to effective vaccines. This review explores the immune responses required to protect against SARS-CoV-2 and the potential for vaccine-induced immunopathology. It describes the profile of the different platforms and the advantages and disadvantages of each approach. The review also addresses the critical steps between promising pre-clinical leads and manufacturing at scale. The issues faced during this pandemic and the platforms being developed to address it will be invaluable for future outbreak control. Nine months after the outbreak began, we are at a point where pre-clinical and early clinical data is being generated for the vaccines, an overview of this important area will help our understanding of the next phases.