Yasufumi Saito

Stay informed with Yasufumi Saito’s coverage and analysis for Fortune.

LONDON, UNITED KINGDOM – 2021/10/06: A health worker holds a vial containing Pfizer Covid-19 vaccine at a vaccination centre.<br />
Fully vaccinated British travelers will no longer need to take a pre-departure PCR test before arriving in England. (Photo by Dinendra Haria/SOPA Images/LightRocket via Getty Images)

Same vaccines, but different fatality rates: why are some COVID outbreaks worse than others?

By Jinshan Hong, Lisa Du, and others