Pennsylvania and New Jersey have stockpiles of Johnson & Johnson vaccine doses that will expire soon — including more than 50,000 doses in Montgomery, Chester, and Bucks Counties that will go bad in five weeks — as a lack of trust in the shot lingers after last month’s pause on its use.

Across Pennsylvania, some vaccine providers have stopped ordering J&J doses. In Montgomery County, some people have shown up to J&J clinics only to leave when they find out which vaccine is being offered. New Jersey officials are trying to figure out how to use up a surplus of doses that will expire in June. And more than 110,000 doses of the single-shot vaccine are stockpiled in Philadelphia, Bucks, Chester and Montgomery Counties alone.

“There is no question that after the pause, J and J is in less demand,” Bucks County Health Director David Damsker said in an email. “It was [a] shame they did that, it really hurt demand.”

Once hailed as a key tool that would help vaccinate people at a time when demand greatly exceeded supply, the J&J vaccine instead has taken a backseat.

More than three weeks after the federal government lifted the pause on the vaccine, and amid general decreased demand for coronavirus shots, vaccination numbers in the region and state indicate Pfizer and Moderna remain favored, and the halt on J&J made many reluctant to get it, even after it was cleared for use by federal health officials. The percentage of the single-dose shots that have been given out in Pennsylvania is much lower than the percentage administered of Pfizer and Moderna, analysis of state data shows.

Providers have lowered their weekly requests for J&J or stopped using it altogether, the Pennsylvania Department of Health said. While J&J vaccinations were on the rise before the pause, the demand in Pennsylvania was low after the ban lifted and has stayed low, said Department of Health spokesperson Mark O’Neill. In New Jersey, 140,000 shots a week were being given before the pause; now, the state is averaging 16,000 J&J shots a week.

The trend is the same nationwide. Of more than 20 million J&J doses available in the United States, 9.7 million were administered as of Wednesday, according to CDC data. The vaccine can be refrigerated at normal temperatures, but it must be used within three months, meaning that without higher demand, providers nationwide could soon face expiring doses.

That means less than half of available doses have been used, compared with 81% of available doses administered for both Moderna and Pfizer. (The supply of the two-dose vaccines is much larger, with more than 265 million doses administered in total.)

A spokesperson for Johnson & Johnson said the single-shot vaccine was a key tool in the global fight against the virus and its variants. “While vaccinations in general have declined in the U.S. in recent weeks, our vaccine is still playing an important role, including among those who wish to be fully vaccinated with one shot,” he said.

With Bucks, Montgomery, and Chester Counties’ J&J doses set to expire June 23, their health departments will have to send extra shots to other providers, ship them back to the state, or discard them. The Pennsylvania Department of Health is planning short-term clinics to use 515 doses that are set to expire May 24, and New Jersey is hoping to transfer doses that need to be used to clinics with high demand.

“We are looking for all opportunities to use the vaccine before it expires,” said Pennsylvania’s O’Neill.

He was unable to provide an estimate of how many doses might be expiring between all providers across the state, and declined to say whether the state was working with providers to make plans for doses. Chester County Health Director Jeanne Franklin said her department has had conversations with the state about returning unused doses that could then be given to other states or providers outside Pennsylvania.

J&J usage was halted for 11 days in April after six cases of a rare blood-clotting disorder were reported in women who had taken the vaccine. After a review by the FDA, it was deemed safe to continue using, and officials said the federal government’s caution should give Americans confidence in the vaccine process. But they also worried that the pause would scare people off, potentially even hurting the country’s chance at herd immunity.

Across the region, some were frustrated last month when they learned the J&J vaccine had been paused and they had to get Pfizer or Moderna instead of the “one-and-done” shot they wanted.

At the time, Dale Mansukh of Levittown said that after weighing the risks against the benefits he still would have gotten the single shot.

“I was excited to get the J&J shot,” he said. “I am disappointed to get one of the alternates. But hey, a vaccine is a vaccine.”

But others were deterred. On the streets of Coatesville on a recent morning, many expressed deep hesitancy they said had been exacerbated by the pause. When a volunteer told residents and business patrons about a nearby clinic, the first question from many was: “What vaccine is it?”

”I wouldn’t take the J&J,” said Sharif Ali, though he noted he was unlikely to get vaccinated at all due to mistrust in a government and health system that has a history of unethical experiments on Black people.

» READ MORE: Vaccination rates keep rising in some Philly suburbs, as others plateau, facing access and hesitancy challenges

When officials nationwide began using J&J in March, they had high hopes that it would help them combat hesitancy and reach underserved or hard-to-reach communities, including people who are homebound or homeless.

Pennsylvania also used its initial supplies of J&J to vaccinate more than 112,000 teachers and school staff, and it is continuing to use the vaccine in targeted initiatives for police officers, firefighters, grocery store employees, and manufacturing and agricultural workers.

» READ MORE: Grassroots efforts take on vaccine barriers across region

But since the pause was lifted, officials say the decreased demand for the shot has been stark. As of earlier this week, fewer than 22,000 people in Bucks, Chester, and Montgomery Counties had received it at county sites since it began being administered (Delaware County did not respond to requests for comment).

Montgomery County Commissioner Chair Val Arkoosh, a physician who got the J&J vaccine in an effort to combat hesitancy, said its J&J clinics have seen such “a significant decline” in attendance that the county this week was making plans to provide Pfizer at all sites.

For the week beginning April 5 — the first week the counties received J&J directly and the week before its pause — Montgomery County administered more than 5,500 doses of the vaccine, according to county data. But when it resumed use the week of April 26, only 991 people opted for the shot, compared with more than 7,700 people who got the Pfizer vaccine the same week.

In Philadelphia, the vast majority of the J&J doses in storage are from the FEMA clinic at the Convention Center and came in an unexpected delivery a few days before the pause, said city health department spokesperson James Garrow. The city is “working through” the 42,000 doses, he said, noting the FEMA sites also have similar stashes of Pfizer.

There are also other potential reasons people are choosing Pfizer or Moderna over J&J: The two others have been available longer, may be better recognized, and appeared more effective in clinical trials. J&J was 66% effective at preventing COVID-19 in trials, while Pfizer was 95% effective and Moderna was 94%. (Experts have warned against comparing the figures because J&J was tested later, after virus variants had emerged.)

Garrow said it was “impossible to say” whether the demand for J&J had slowed more than that for Pfizer or Moderna because demand for all vaccines has been down “since interest dropped off.”

And state and local officials said there isn’t an urgent need for people to take J&J: There were about 50,000 stockpiled doses of Pfizer and Moderna in the suburbs, excluding Delaware County, as of Monday; officials said that wasn’t as concerning as unused J&J doses because the administration rate is higher.

Pennsylvania and New Jersey health officials are hoping providers won’t have to throw out any expired doses.

“Now is a great time to get vaccinated,” O’Neill said.

Staff writers Allison Steele and Jason Laughlin and graphic artist Chris A. Williams contributed to this article.