The wrath of COVID-19 will likely stretch into the years ahead, and it’s plausible that the debate over risks related to COVID-19 vaccines will do the same. The 2009 swine-flu strain never really went away, and many scientists now believe that this coronavirus is here to stay as well. But the current pandemic is unlike any public-health crisis in our lifetimes, and it has led to an unprecedented pace of scientific progress. This could lead us to a quicker, more definitive resolution of the vaccine-related clotting issue. If that happens, what’s been learned will help us continue to navigate the promises and pitfalls of new vaccine technologies, and it might even shed light on how clotting goes awry because of COVID-19 itself.