President Biden will announce on Wednesday afternoon that he has directed his administration to purchase an additional 100 million doses of the Johnson & Johnson coronavirus vaccine, the New York Times reports.

Why it matters: Biden's goal is to secure enough supply to vaccinate children and — if necessary — administer booster shots to increase protection against new variants of the virus, according to the Times.

• The announcement comes a week after the president said the U.S. will have enough vaccines available for 300 million adults by the end of May.
• Unlike Pfizer and Moderna's vaccines, the J&J shot only requires one dose. The U.S. government had previously purchased 100 million doses from the company.

The state of play: The doses are expected to be delivered in the second half of the year, two officials told the Times.

• Biden will make the announcement Wednesday afternoon during his meeting in the White House with the CEOs of Johnson & Johnson and Merck.
• The Biden administration said last week that the two rival pharmaceutical companies would be teaming up to boost supply of J&J's one-shot vaccine.

The big picture: The U.S. has administered more than 93 million vaccine doses as of Wednesday afternoon, according to a Bloomberg tracker. More than 18% of Americans have received their first dose, with states currently administering vaccines at a rate of about 2.1 million per day.