The Covid-19 pandemic has continued for over two years now. Currently, the US only has 67% of its population fully vaccinated, compared with countries like China and Vietnam, where well over 80% of the population is fully vaccinated. Some hesitancy may be in part due to the perception of the speedy development of vaccines.

Covid-19 vaccines and therapeutics were developed at a rapid speed in response to the pandemic, all taking far less time than vaccines and therapeutics on average that were developed for other viral infections. As seen in Figures 1 and 2, the average duration of completed trials for viral infections was much longer than that for Covid-19.

Trials testing vaccines for viral infections other than Covid-19 took about three times longer than those for Covid-19, while trials testing therapeutics for viral infections other than Covid-19 took about five times longer than those for Covid-19. The biggest difference was seen in Phase IV trials; this is unusual, as Phase IV trials typically enrol a much larger subject pool to test long-term safety and effectiveness.