The first delivery of Moderna Inc’s COVID-19 vaccines arrived in Japan on Friday, public broadcaster NHK reported, citing airline officials.

Japan has so far only cleared Pfizer Inc’s coronavirus vaccine and is expected to approve Moderna’s in May.

“Once approved, we will set up a system for inoculations immediately,” health minister Norihisa Tamura said at a press conference.

The vaccines are expected to be used at locations such as a mass inoculation site that will be set up in central Tokyo by the Self-Defense Forces on May 24.

The shipment arrived aboard a Japan Airlines flight to Kansai International Airport in Osaka Prefecture, western Japan, from Brussels.

Moderna’s vaccine can be stored for up to six months at -20 degrees Celsius, though it is expected to be stable for 30 days at normal fridge temperature of 2 to 8 degrees Celsius (36 degrees Fahrenheit to 46 degrees Fahrenheit). Those are less onerous requirements than Pfizer’s, which must be stored at ultra-cold temperatures of -70 degrees Celsius, but can last in normal refrigeration for up to five days, or 15 in a thermal shipping box.

The vaccine was shown to be nearly 95% effective in clinical tests overseas, with a requirement of two shots that need to be taken 28 days apart, which is a longer interval than for the Pfizer vaccine.

The ministry has signed a contract to receive enough doses of the Pfizer vaccine for 25 million people by September.

Over 2.2 million people, including medical workers and elderly people, have received their first shots in Japan.

Reuters/JIJI Press