Even as federal health regulators lifted an 11-day pause on the Covid-19 vaccine made by Johnson & Johnson (J&J), the rate of new vaccinations across the United States is declining for the first time since February.

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Pause on J&J's vaccine lifted

CDC and FDA on Friday officially lifted their recommendation to pause distribution of J&J's vaccine.

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The pause began on April 13, after six people who received J&J's vaccine—out of the roughly 7.2 million people who had received the shot—developed a rare and severe type of blood clot called cerebral venous sinus thrombosis (CVST).

The condition typically involves severe headaches, abdominal pain, leg pain, or shortness of breath, with symptoms most often occurring around six days after vaccination, the New York Times reports. It can be fatal if it leads to bleeding in the brain.

On Friday, Tom Shimabukuro, deputy director of CDC's immunization safety office, announced that more cases of CVST had been found during the pause. In total, CDC has identified 15 cases, of which 13 were in women ages 18 to 49 and two were in women ages 50 and older.

Shimabukuro added that the agency was still reviewing other potential cases of CVST, including some affecting men.

CDC's advisory panel voted 10-4 to resume use of J&J's vaccine and to add a warning label about the risk of CVST in young women that says the "chance of having this occur is remote."

"Both agencies have full confidence that this vaccine's known and potential benefits outweigh its known and potential risks in individuals 18 years and older," Janet Woodcock, acting commissioner of FDA, said.

"This is a serious adverse event. We need to continue to ensure that awareness is raised," Grace Lee, a member of the advisory panel and a pediatrician at the Lucile Packard Children's Hospital, said. "But I also think that we have to come out with a clear recommendation."

Peter Marks, FDA's chief of drug evaluation, said "there'll be a lot of scientific work" in the coming weeks to understand why the vaccine may be tied to blood clotting.

Rates of new vaccinations are declining

Even as many states began resuming distribution of the J&J vaccine, the overall rates of new vaccinations had begun to decline nationwide. Daily doses administered last week fell about 13% compared to the week before, from around 3.38 million doses a day on average to around 2.95 million, the Times reports.

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According to the Washington Post, this is the first time the United States has seen a significant drop in vaccination rates since a brief dip in February, when winter storms led to the closure of vaccination sites.

The decline has been especially prevalent in the South, with average daily vaccinations dropping last week by more than 30% in Georgia and South Carolina and by around 25% in Texas. However, some states outside of the South—including Alaska, Maine, and New Hampshire—also saw significant declines in new vaccinations, the Post reports.

Meanwhile, the pace of vaccine administration is still climbing in a number of states, including California, Delaware, the District of Columbia, Hawaii, Kentucky, Puerto Rico, and Utah, according to the Post.

Some experts have suggested the pause on J&J's vaccine could partly be to blame for slowing vaccination rates. Larry Bergner, administrator for the health department in Newton County, Missouri, said demand had been declining before the pause, but he worried the pause made people in the area even more hesitant to get a vaccine.

"Some tell me that they had planned on getting vaccinated until J&J was halted," he said. "Now, they say they are going to hold off until they feel confident that all vaccines are safe."

However, polling suggests that vaccine hesitancy nationwide hasn't increased significantly. According to the Washington Post, recent surveys found that between 65% and 70% of Americans say they're likely to receive a vaccine, roughly unchanged since the pause began.

To encourage more people to get vaccinated, President Joe Biden last week introduced a tax credit for small businesses to offset the costs of providing employees with paid leave to get a vaccine.

Health officials said that to ensure the vaccine rollout continues making progress, it will be critical to ramp up efforts to vaccinate difficult-to-reach groups, such as homebound individuals, people in rural communities, and people who are hesitant to be vaccinated.

"This will be much more of an intense ground game where we have to focus on smaller events more tailored to address the needs and concerns of focused communities who have different sensitivities and different needs," Steven Stack, commissioner of the Kentucky Department of Health, said (AP/Modern Healthcare, 4/25; Wamsley, NPR, 4/23; Grady et. al, New York Times, 4/23; Anthes et. al, New York Times, 4/23; Morse, Healthcare Finance News, 4/23; Weise/Weintraub, USA Today, 4/25; Healy, Los Angeles Times, 4/23; Keating et. al, Washington Post, 4/21; Yeip et. al, Wall Street Journal, 4/24).