Japan began its long-awaited coronavirus vaccination program Wednesday.

The first shots took place at a Tokyo hospital just hours after the hospital received the Pfizer-BioNTech vaccine. As many as 40,000 doctors and nurses across the nation will receive the first doses of the vaccine, with the eventual goal of inoculating a total of 3.7 million medical personnel by March, followed by about 36 million citizens 65 years of age and older.

Japan's vaccination program is off to a slow start, with health authorities only formally approving use of the two-dose Pfizer-BioNTech drug on Sunday. Officials asked Pfizer to carry out further tests on the vaccine in addition to earlier tests that had been conducted in several other countries. Taro Kono, the country's vaccine minister, told reporters Tuesday the additional testing was conducted to reassure the Japanese people of its safety.

Vaccinations are not compulsory in Japan, and while Kono voiced confidence he could reach front-line workers and elderly people, he acknowledged he needed to formulate a plan for successfully reaching younger people and encourage them to get the shot.

A medical worker fills a syringe with a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine as Japan launches its inoculation campaign, at Tokyo Medical Center in Tokyo, Feb. 17, 2021.

Along with Pfizer-BioNTech, Japan has also signed contracts to procure millions of doses of the vaccine from AstraZeneca and Moderna, enough in all for 157 million people. The country is hoping to get enough people vaccinated in time for the postponed Tokyo Summer Olympic Games, which are scheduled to begin in July.

Japan is the last member of the Group of Seven (G7) industrialized nations to begin the shots.

Meanwhile, about 80,000 doses of the new COVID-19 vaccine developed by U.S. drugmaker Johnson & Johnson arrived in Johannesburg, South Africa, late Tuesday night. The government will begin administering the Johnson & Johnson vaccine to health care workers later this week as part of an observational study. A total of 500,000 doses are expected to be shipped to South Africa within the next few weeks, along with another 20 million doses of the Pfizer-BioNTech vaccine.

South Africa had purchased 1 million doses of the two-shot vaccine developed by AstraZeneca and Oxford University, but abandoned plans to use the drug after a study revealed that the vaccine was less effective against a variant of the coronavirus found in the country. Health Minister Zweli Mkhize told parliament Wednesday that South Africa will share the AstraZeneca-Oxford vaccine with the African Union, which will distribute it throughout the continent.

The single-dose Johnson & Johnson vaccine has not been formally approved for use by any country, but the company says results of a late-stage clinical trial shows it is 85% effective in preventing serious illness or death from COVID-19, even against the South African variant.

In the United States, President Joe Biden said Tuesday night the country will have more than 600 million doses of coronavirus vaccines, enough to inoculate "every single American" by the end of this July. Biden made the pledge during a question-and-answer session in Milwaukee, Wisconsin that was televised on cable news network CNN.

When asked by moderator Anderson Cooper when the United States will return to normal, Biden said by next Christmas "we'll be in a very different circumstance, God willing, than we are in today." The White House announced earlier Tuesday that the federal government will increase the amount of COVID-19 vaccines that states receive each week from 11 million doses to 13.5 million doses.

The president also said that states should prioritize public school teachers in their vaccination efforts as part of a strategy to reopen schools to full-time in-person classes.