The federal government’s call for a pause on using Johnson & Johnson’s Covid-19 vaccine could last at least another week, further complicating efforts by federal and state health officials to reschedule appointments, and reassure jittery Americans that the vaccine is safe and effective.
The Centers for Disease Control and Prevention’s independent vaccine advisory panel, known as the Advisory Committee on Immunization Practices, or ACIP, has been scheduled to meet for a second time since shots were halted, next Friday, to discuss safety data related to a small number of blood-clotting cases in Johnson & Johnson vaccine recipients. It is unclear whether the vaccine was responsible for the clots.
The public, six-hour meeting could conclude with a vote, for example, to recommend to continue the pause, to modify the F.D.A.’s authorization of the single-dose vaccine or to rescind the pause altogether. The federal government could then act quickly to follow the guidance.
“We recognize the critical importance of moving quickly. That’s why we will have two unscheduled ACIP meetings in a 10-day period,” Dr. Rochelle P. Walensky, the C.D.C. director, said at a White House news conference Friday.
She said that the C.D.C. had contacted over 10,000 providers “to ensure that they know what kinds of cases to look for.”
The panel’s decision was a key part of the federal government’s still mostly undefined plan for resolving the pause, which Dr. Janet Woodcock, the acting commissioner of the F.D.A., told reporters on Tuesday might last only “a matter of days.” But the panel of expert advisers, whose recommendations carry significant weight with state health departments and physicians, decided Wednesday to wait on a vote while they take more time to assess a possible link to the rare but serious blood-clotting disorder.
Dr. Anthony S. Fauci, the government’s top infectious disease expert, told lawmakers at a hearing on Thursday that “hopefully we’ll get a decision quite soon as to whether or not we can get back on track with this very effective vaccine.” State health departments have rescheduled appointments and substituted two-dose vaccines made by Pfizer-BioNTech and Moderna — a plan that White House officials have referenced as a quick way to make up for the gap.
While Johnson & Johnson’s vaccine has accounted for a fraction of U.S. vaccinations, it has been a key tool in the Biden administration’s strategy. The shot can be kept at normal refrigeration temperatures for three months, and at one dose, allowed for people to dispense with vaccination in a single go. Some public health officials worry the pause may deepen hesitancy. And there are concerns about the risks posed to the global vaccination drive in countries that can ill afford to be particular about shots.
In the United States, the pause has had immediate consequences for local officials, who have worked to vaccinate vulnerable populations with the shot: homeless people in Baltimore, homebound residents in the District of Columbia, the poor and uninsured in Massachusetts and rural residents in a number of states.
In New York City, Mayor Bill de Blasio said Friday on WNYC that the city’s overall vaccination campaign had not been derailed by the pause, but the greatest disruption had been to the city’s program for homebound people, which relied on the Johnson and Johnson vaccine and has ground to a halt for now.
The city estimated that there are 23,000 homebound candidates for the program, and said that its vaccination teams have so far made 3,600 visits. The effort has been ramping up, and has been recently vaccinating 1,200 people per week. On each visit, the program allows for the homebound senior to get the shot, along with anyone else in the household who is eligible. Mr. de Blasio said that he hoped the city would again be able to use the Johnson & Johnson vaccine for that population, but if not, the program would continue with the other authorized vaccines.
About 7.8 million Americans have received the Johnson & Johnson shot, with about 10 million doses unused.
Setbacks with the vaccine, including a mix-up in a Baltimore plant that recently contaminated up to 15 million doses of it, have caused the White House to revise its math in projecting when the nation will have enough doses to cover every American adult, which President Biden had predicted would happen by the end of May.
The White House press secretary, Jen Psaki, said on Thursday that there would be enough doses to cover 80 percent of the adult population by that point, or likely enough for every adult who wants one. She added that there would be enough for 90 percent of the population by the end of July.
Sheryl Gay Stolberg, Daniel E. Slotnik and Sharon Otterman contributed reporting.