Several states swiftly pause the use of Johnson & Johnson’s vaccine after a federal advisory.

Authorities in Ohio, New York, New Jersey, Connecticut, Massachusetts, Maryland, Nebraska, Georgia, Indiana, Texas and Virginia said Tuesday that they would heed the call from federal health officials to stop the Johnson & Johnson vaccine from being administered after six Interrupt women in the United States developed a rare blood clot disorder within about two weeks of vaccination.

CVS, the nation’s largest pharmacy chain, also said it would stop using Johnson & Johnson vaccinations immediately and email customers if their appointments were being canceled. A spokesman said CVS will postpone appointments “as soon as possible.”

Ohio Governor Mike DeWine and the state’s chief health officer said they advised all state vaccine providers to temporarily stop using the single-dose vaccine. New York Health Commissioner Dr. Howard Zucker said the state will stop using the Johnson & Johnson vaccine while the Food and Drug Administration and Centers for Disease Control and Prevention assess safety risks.

Connecticut health officials said they told vaccine providers to postpone scheduled appointments and offer an alternative option if they had the supply.

The CDC’s external advisory board has scheduled an emergency meeting for Wednesday.

White House Covid Coordinator Jeff Zients said Tuesday the hiatus will not have a material impact on the country’s vaccination campaign, which has been accelerating in recent weeks, as a surge in new virus cases threatens a fourth possible spike. Many states have already given all adults the right to vaccinate, while others are planning to do so by next week.

“For the past few weeks we’ve provided more than 25 million doses of Pfizer and Moderna each week, and in fact we will be delivering 28 million doses of these vaccines this week. This is more than enough to continue the current vaccination rate of 3 million shots per day, ”Zients said in a statement.

While the response to the Johnson & Johnson shot is rare, questions about the safety of the shots could add to the vaccine’s hesitation.

Nearly seven million people in the United States have received shots from Johnson & Johnson to date, and around nine million more doses have been sent to the states, according to the Centers for Disease Control and Prevention. The six women who developed blood clots were between 18 and 48 years old. One woman died and a second Nebraska woman was hospitalized in critical condition.

“Right now, these adverse events seem extremely rare,” said Dr. Peter Marks, director of the Food and Drug Administration’s Center for Biological Research and Evaluation, and Dr. Anne Schuchat, deputy chief executive officer of the CDC, in a joint statement on Tuesday. “People who have received the J&J vaccine and develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks of vaccination should see their doctor.”

Like many states, New York had already prepared for a sharp drop in supplies of the Johnson & Johnson vaccine after federal officials said supplies would be limited due to a production problem at a Baltimore manufacturing facility. On Friday, Governor Andrew M. Cuomo said New York would expect 34,900 Johnson & Johnson admissions, an 88 percent decrease from the previous week.

Dr. Sugar, New York’s health commissioner, said the state will meet appointments at state bulk vaccination sites for the Johnson & Johnson vaccine by giving people the Pfizer BioNTech vaccine instead. This vaccine requires two doses, and it was not immediately clear how the state would deal with the added burden on its supply.

New York City Mayor Bill de Blasio said the city will work to reschedule appointments at city-run vaccination sites and give those people the Pfizer or Moderna vaccines instead.

“Each site was instructed this morning not to take any more J&J shots,” he said at a press conference.

Mr Cuomo received the Johnson & Johnson vaccine last month at a public appearance in Harlem that he launched to build confidence in the vaccine’s rate of effectiveness and to address vaccine hesitation.

Regulators in Europe and elsewhere are concerned about a similar issue with another coronavirus vaccine developed by researchers from AstraZeneca and Oxford University. This vaccine has not been approved for use in an emergency in the United States.