A White House official warned Johnson & Johnson Covid vaccines will be scarce until a troubled plant gains regulatory approval

Supplies of Johnson & Johnson’s one-dose coronavirus vaccine will be extremely limited until federal regulators approve production at a Baltimore manufacturing plant under scrutiny, the White House’s pandemic response coordinator said Friday.

With allocations of the Johnson & Johnson vaccine set to plunge by 86 percent next week, governors across the country warned that the loss of the supplies they were counting on would set back their vaccination drives, which have used the shot in more transient, isolated and rural areas where the one-dose vaccine has appealed to many Americans. The other two vaccines, made by Moderna and Pfizer-BioNTech, continue to flow out to the states at high volume.