Researchers in Tokyo are developing a “dream” COVID-19 vaccine that offers lifetime efficacy, in what would be a game-changer as the fight against the coronavirus drags on into its third year.

At a time when it appears most COVID-19 vaccines will require periodic boosters due to a decline in recipients' antibody levels, the creation of a vaccine with lifetime efficacy could lead to huge financial savings globally and give the world an upper hand against the coronavirus, which has infected more than 270 million people and claimed more than 5 million lives around the world.

Soon after the pandemic began, in early 2020, Michinori Kohara, emeritus investigator at the Tokyo Metropolitan Institute of Medical Science, wondered if it was possible to develop a vaccine based on the tried and tested smallpox vaccine — which helped the world eradicate the deadly disease. The vaccinia virus used in the smallpox vaccine is a subject he has worked on for over three decades, and Kohara knows firsthand how significant a vaccine that gives strong protection for life can be.