New technologies and scientific knowledge have drastically compressed the timelines of vaccine discovery. It was apparent by 2011 that high-throughput methods and parallel testing of multiple approaches would hasten the identification of candidate vaccines and formulations as well as their development (R. Rappuoli and A. Aderem Nature 473, 463–469; 2011).
In the 1980s, only killed, live-attenuated, toxoid or polysaccharide vaccines were available. A decade later, recombinant DNA technologies, conjugation and reverse vaccinology boosted research into new vaccines. At a meeting in Rockville, Maryland, in 2019, vaccine experts from academia, regulatory agencies and industry agreed that new technologies to shorten the long and expensive timelines of vaccine development were ready to be implemented (see S. Black et al. Semin. Immunol. 50, 101413; 2020).
Indeed, vaccines against SARS-CoV-2 were developed at an unprecedented speed. The key factor was the parallel execution of the preclinical, toxicology and phase I, II and III trials needed to bring a candidate to licensure and still ensure safety and efficacy.
Open questions remain on why we needed a pandemic to implement something that was already scientifically mature and whether we can maintain this high speed in future (see Nature 589, 16–18; 2021).
