As shortages of the COVID vaccine plague the U.S., the rollout of Johnson & Johnson’s shot is not expected to make that much of a dent in the problem, according to White House officials.

Jeffrey Zients, White House’s COVID-19 response coordinator, said during a press call on Wednesday that “there is not a big inventory of Johnson & Johnson." He warned, "There’s a few million doses that we’ll start with.”

Zients went on to say that Johnson & Johnson is committed to providing 100 million doses by June, but it is expected that deliveries will most likely be “back-end loaded” with the government working to boost its supply.

In March, the federal government provided Johnson & Johnson with $456 million in funding for its COVID vaccine program, Reuters said. In August, another $1 billion was paid to the company to fund the development of the vaccine in exchange for 100 million doses of the drug with the option to purchase 200 million doses.

Johnson & Johnson is anticipated to receive Food and Drug Administration (FDA) regulatory authorization for its COVID vaccine within the next few weeks, Zients said during the press call. Johnson & Johnson’s vaccine was shown to provide an efficacy of up to 66% in one dose.

According to Johnson & Johnson, once authorization is provided from the FDA, it expects to deliver 100 million doses of the vaccine to the U.S. in the first half of 2021.

The U.S. has seen challenges with its COVID vaccine supply despite Pfizer and Moderna-BioNTech promising to deliver 200 million doses of their drug by the end of March, Reuters reported. The news outlet said that fewer than 72 million doses have been shipped across the nation.

The Centers for Disease Control and Prevention said it has administered over 56.2 million doses of the COVID vaccine to over 40.2 million people. Over 15.4 million people have received two doses of the vaccine to date, according to the agency.

President Biden has said his goal is to vaccinate over 100 million people with the COVID vaccine in his first 100 days in office.

On Thursday, Biden announced that the U.S. had secured 100 million more doses of the Pfizer-BioNTech vaccine and 100 million more doses of the Moderna vaccine. This takes the current shot supply to 600 million doses, which is enough to vaccinate 300 million people with two doses, CNBC reported.

The Johnson & Johnson COVID vaccine is slated to be discussed by the FDA’s Vaccines and Related Biological Products Advisory Committee on Feb. 26. It could be approved as early as the next day, officials said.

Johnson & Johnson vaccine The Johnson & Johnson vaccine is pictured. Photo: GETTY IMAGES NORTH AMERICA / Michael Ciaglo