Just 36% of people under age 65 who received two shots of a COVID-19 vaccine in Japan were protected against infection, yet the rate jumped to nearly 70% for those who got a booster shot, according to a new study from Nagasaki University.

The study, presented on Wednesday to the health ministry advisory panel on coronavirus measures, underscores the importance of getting a third jab, panel chair Takaji Wakita told reporters.

“We know that the coronavirus vaccine is more effective after three doses amid the spread of the omicron variant of the coronavirus,” Wakita, also director of the National Institute of Infectious Diseases, was reported as saying by Jiji Press. “We need to keep recommending that people get the third dose.”