Japan is set to receive about 100 million doses of COVID-19 vaccine from Pfizer Inc. across May and June, the minister in charge of vaccination efforts said Friday, enough for nearly half of its population.

The shipments from the drugmaker's factory in Belgium will need to be individually approved under the European Union's export controls, Taro Kono said at a press conference.

Prime Minister Yoshihide Suga has pledged to secure COVID-19 vaccines for Japan's population of 126 million within the first half of 2021.

The vaccine developed by Pfizer and its partner BioNTech SE, the only one the health ministry has approved so far, consists of two shots, meaning 100 million doses will be enough for 50 million people.

Kono said after negotiations with Pfizer, Japan expects to receive nearly 1.8 million vials, which could yield up to about 10.7 million doses using low dead space syringes, per week in May, with shipments to further increase in June.

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Such syringes, capable of drawing six doses from a vial, will be used to administer the second shots for health care professionals, while typical ones can only extract five doses from a vial. The vaccine for their first shots will be shipped from April 12.

The more efficient syringes will be used for inoculating elderly people as well.

Japan is in the process of inoculating 4.8 million health care workers and plans to expand the vaccine rollout to people aged 65 or older, a group of about 36 million, in mid-April. People with underlying conditions such as diabetes and those working at elderly care facilities will follow.

Shots for the elderly will be delivered to municipalities by the end of June, Kono said.

Japan has lagged behind other countries such as the United States and Britain in its vaccine rollout amid a supply shortage due to production delays at Pfizer's factory and the European Union's export controls, which are set to run until the end of June.

The fifth batch of the Pfizer vaccine, about 420,000 doses, will arrive in Japan on Monday, according to Kono. The country received its first shipment last month.

Public skepticism over side effects could also hold up the effort, with only 63.1 percent of respondents in a Kyodo News poll conducted last month saying they want to be inoculated.

Among the 181,184 people in the country who have received a shot, 37 claims of anaphylaxis, a severe and potentially fatal allergic reaction, were reported as of Thursday, but one of them was retracted, according to the health ministry. Kono added all of them had recovered.

As for 17 cases reported by Tuesday, only seven were confirmed as being anaphylaxis following intricate exams based on international standards, the ministry said.