TOKYO - A health ministry panel on Friday greenlit Pfizer Inc.'s coronavirus vaccine for use in Japan, with health minister Norihisa Tamura saying it could become the first to receive formal approval from the country as early as Sunday.

The government aims to start vaccinations mid-next week for around 20,000 doctors and nurses who have consented to receive the shots, Tamura said.

Prime Minister Yoshihide Suga told reporters he would ensure the vaccines reach the public "as soon as possible."

On Friday, the first batch of some 400,000 doses arrived at Narita airport to the east of Tokyo at around 10:20 a.m. on an All Nippon Airways Co. flight from Brussels.

An airplane carrying a batch of the Pfizer Inc. coronavirus vaccine arrives at Narita airport from Brussels on Feb. 12, 2021. (Kyodo)

It had been widely reported that the first doses would arrive from Belgium, where they were manufactured, on Sunday, while the Health, Labor and Welfare Ministry had initially planned to move ahead with formal approval on Monday.

"We've long known that vaccines would play a large role in fighting the novel coronavirus. This approval is very significant for that battle going forward, for safeguarding the health of the people," Tamura told reporters.

The health ministry panel gave the go-ahead considering the urgency of the ongoing pandemic and the fact that the vaccine, jointly developed by U.S. pharmaceutical giant Pfizer and its German partner BioNTech SE, has already been administered in several countries, including the United States.

The roughly 20,000 doctors and nurses from 100 hospitals across the country getting the first shots are set to participate in a study aimed at tracking potential side effects and the frequency with which they occur.

Photo taken from a Kyodo News helicopter on Feb. 12, 2021, shows cargo being unloaded at Narita airport near Tokyo from an airplane that transported from Brussels the first batch to arrive in Japan of the coronavirus vaccine developed by U.S. pharmaceutical giant Pfizer Inc. (Kyodo) ==Kyodo

An additional 3.7 million frontline health workers will begin being inoculated in mid-March, followed by people aged 65 and older from April at the earliest. People with pre-existing conditions and those working at elderly care facilities will be next, then finally the general population.

Pfizer and its German partner have conducted clinical trials on approximately 43,000 people abroad and found its vaccine is 95 percent effective. In Japan, it conducted a trial involving about 160 people.

The government has agreements in place with Pfizer, AstraZeneca Plc and Moderna Inc. to receive more than enough doses to cover Japan's population of 126 million.

But tightening export controls by the European Union of Pfizer vaccines produced in the bloc make it unclear when and in what amount Japan will receive subsequent batches. Tokyo aims to secure needed supplies through negotiations with the union.

About 20,000 ultracold freezers are slated to be set up at medical facilities across Japan to store the Pfizer vaccine, which needs to be kept at a temperature of about minus 75 C. The AstraZeneca vaccine can be stored at 2 to 8 C, making it easier to handle, but it is only around 70 percent effective.