The agreement with the British drugmaker comes after Japan announced a deal last week to buy 120 million doses of a COVID-19 vaccine candidate developed by Pfizer Inc and BioNTech SE.

"I understand one or two doses are effective per person," Health Minister Katsunobu Kato told reporters.

"If each person receives two injections, this would cover 60 million people."

Japan is the latest country to sign up for AstraZeneca's vaccine, known as AZD1222, which is under development in partnership with the University of Oxford. The pharmaceutical firm has been in talks with Russia, Brazil and others about supply deals for its potential vaccine.

In a statement, AstraZeneca said it would produce the vaccine substance in Japan with JCR Pharmaceuticals Co, while also importing additional substance from overseas.

Daiichi Sankyo Ltd, Daiichi Sankyo Biotech Co, Meiji Seika Pharma Co and KM Biologics Co will support supply in Japan, the company said.

As Japan procures vaccines from abroad, it is also developing its own vaccine for the novel coronavirus, with AnGes Inc and Osaka University working on a DNA vaccine, while Shionogi & Co is working on a recombinant protein type.

The University of Tokyo and Daiichi Sankyo are developing an mRNA version.

There are currently no approved vaccines or treatments for the illness caused by the new coronavirus, but about a dozen vaccines from more than 100 candidates globally are being tested in humans.

(Corrects headline to read COVID-19)

(Reporting by Kiyoshi Takenaka and Naomi Tajitsu; editing by Jason Neely and Kim Coghill)