Given the incredible speed in which vaccine development for COVID-19 is occurring, it merits thinking back on the typical development and approval time of previous vaccines. Puthumana et al. (2020) reviews 21 vaccines approvals since 2010. They find that:
…most novel vaccines approved by the FDA required about 8 years of clinical development and were based on evidence from a median of 7 clinical trials, including at least 2 pivotal efficacy trials that were randomized, masked, and used a comparator group. These pivotal efficacy trials enrolled a median of 5000 patients, who were followed up for serious adverse events for at least 6 months. Given the urgency of developing a COVID-19 vaccine, trials will need to be larger than those supporting prior vaccine approvals and include sufficient follow-up time for emergence of adverse effects.
Bringing a COVID vaccine to market in 1-2 years would be a remarkable accomplishment given previous vaccine development timelines.