The White House is looking to governors to boost confidence in the Johnson & Johnson coronavirus vaccine as the company ramps up supply in the U.S. 

Several state leaders have taken the one-dose shot in recent weeks, and some have said it was an intentional decision to show the newest vaccine available to the public is safe and effective.

The decisions came after White House aides told staffers from governors’ offices last month to encourage their bosses to get vaccinated with the Johnson & Johnson shot, according to two people on a recent call.

The Johnson & Johnson vaccine particularly needs a confidence boost this week after it was reported that human error at a manufacturing plant ruined 15 million doses. The snafu did not cause issues with any doses already shipped or administered, and Johnson & Johnson maintained it still expects to meet its goal of delivering 100 million doses to the U.S. by the end of June.

But governors and the White House have been mobilizing to support the vaccine since the middle of March, when the Johnson & Johnson shot first started to become more widely available.

The White House convened a call with communications staff from governors offices around the country in mid-March, according to sources on the call, shortly after the Food and Drug Administration signed off on the Johnson & Johnson vaccine and the first shipments to states went out. A White House official said the administration wanted to spotlight the Johnson & Johnson shot "right out of the gate."

Nevada Gov. Steve Sisolak (D), Illinois Gov. J.B. Pritzker (D), Virginia Gov. Ralph Northam (D), Minnesota Gov. Tim Walz (D) and Oklahoma Gov. Kevin Stitt (R) are among the state leaders who have received the Johnson & Johnson vaccine since mid-March.

Not every governor opted for the Johnson & Johnson shot because of the White House ask, but some said it influenced their choice.

"Governor Northam's decision to get the Johnson & Johnson vaccine two weeks ago was intended to increase public confidence in that particular vaccine," said Marissa Astor, a spokesperson for Northam. "He felt it was important to demonstrate that there are three safe and effective vaccines available, including Johnson & Johnson."

A spokesperson for Walz stressed that the governor wants to assure Minnesotans that "the best vaccine is the one you’re offered."

Walz's decision to get the Johnson & Johnson shot was intentional, the spokesperson said, but it was made before White House officials specifically encouraged governors to get that vaccine.

Stitt, who got the vaccine this week, got the Johnson & Johnson shot because the state health department had it available, an official with his office said. Oklahoma is among the top 10 states for vaccines administered, the official noted, and Stitt wanted to publicly encourage residents to get their shot.

The White House official was adamant that the administration has seen enthusiasm from the public about the Johnson & Johnson shot. Outreach to governors has been part of a multipronged strategy to engage government, religious and cultural leaders to encourage the public to get any of the three available vaccines.

Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases and Biden's top medical adviser, also did a video posted by the White House last week in which he laid out the basics about the Johnson & Johnson vaccine and assured the public it was safe and effective.

“I would definitely take the Johnson & Johnson vaccine," Fauci said, noting it's "virtually 100 percent protective" against hospitalization and death. "This is a vaccine that works, and it only requires one dose.”

The Johnson & Johnson shot requires just a single dose, compared to the Moderna and Pfizer vaccines, which require two doses a few weeks apart. It can also be stored at higher temperatures than the other two vaccines, making it easier to ship and distribute.

Yet the shot, which was the third vaccine authorized for use in the U.S., has struggled with public perception of its efficacy. 

Trial data showed the Johnson & Johnson shot was slightly less effective in preventing infection than the Moderna or Pfizer shots, though it did completely prevent hospitalization and death four weeks after inoculation.

Officials have cautioned that the circumstances of the trials for the different vaccines varied. For example, the Johnson & Johnson shot was tested against variants and proved effective against those newer strains of the virus.

The White House has also had to overcome skepticism about the Johnson & Johnson vaccine from some leaders in the Catholic faith because it was developed from stem cells obtained during two abortions decades ago.

President Biden on Wednesday urged religious leaders in a video call to "spread the word" to their congregations that the vaccines are safe and to get the shot when it's their turn.

Health officials have stressed that all three of the available vaccines — Moderna, Pfizer and Johnson & Johnson — are safe and that Americans should feel comfortable getting any one of them.

Reid Wilson contributed.