The health ministry has secured the wrong syringes for efficient use of Pfizer Inc.’s COVID-19 vaccine, a discovery that could force a review of the inoculation program.

A special syringe is needed to extract six doses from one vial of the vaccine.

But ministry officials checked the domestic stock of syringes and found that most of them can only extract five doses per vial, health minister Norihisa Tamura said at a Lower House Budget Committee meeting on Feb. 9.

These syringes would still contain some of vaccine in the needle after injection. They are to be disposed of after each use.

The ministry has started looking for the special syringes, officials said.

Japan has signed a contract with Pfizer, a U.S. pharmaceutical giant, to receive 144 million doses of its COVID-19 vaccine, enough to inoculate 72 million people.

“Our deal with Pfizer is that they provide us with 144 million doses,” a ministry official said. “We will discuss the matter with Pfizer. It is too early to tell if the total number of doses will be reduced.”

However, a senior ministry official hinted at the possibility that fewer people will be inoculated with Pfizer’s supply.

“We have no option but to go ahead with the premise that we can inject only five people per vial,” the official said.

A health ministry meeting on Feb. 12 will discuss approval of Pfizer’s vaccine. If approved, inoculation of health care workers will start as early as next week.

The ministry will revise guidelines of the vaccination process for local governments by the end of this week.

According to the ministry, each vial contains the vaccine stock solution. Health care workers dilute the vaccine stock solution in saline, then insert a syringe into the vial to extract a certain amount for inoculation.

Pfizer has told the ministry that six doses can be taken from one vial. Ministry officials repeated Pfizer’s explanation at meetings with local government officials in January.