Japan is scrambling to secure special syringes to maximise the number of Covid-19 vaccine shots used from each vial, but manufacturers are struggling to ramp up production quickly, raising fears that millions of doses could go waste.

Japan, with a population of 126 million, last month signed a contract with Pfizer Inc to procure 144 million doses of its vaccine, or enough for 72 million people, with the vaccination campaign set to start on Wednesday.

One vial is meant for six shots, Pfizer says, but it takes special syringes that retain a low volume of solution after an injection to extract six doses, while only five shots can be taken with standard syringes that the government has stored up in preparation for the inoculation drive, according to Reuters.

“We are still trying to secure these special syringes,” Chief Cabinet Secretary Katsunobu Kato said.