How Can A Safe COVID-19 Vaccine Be Made So Quickly?

Although vaccine development typically takes many years, scientists had already begun research for coronavirus vaccines during previous outbreaks caused by related coronaviruses such as SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome). That earlier research provided a head start for rapid development of vaccines to protect against infection with the novel coronavirus SARS-CoV2, the virus that causes COVID-19.

They have also overlapped different stages of the process, such that manufacturing was already well underway whilst the clinical trials were still ongoing; additionally, information was provided to many regulators on a rolling basis, rather than all at once at the end of the trial periods.