New Jersey’s vaccine rollout is mostly working. In Pennsylvania, it’s more complicated.

Marilyn Jackson walked to the lobby of her Camden apartment building on March 12 to get vaccinated against the coronavirus, grateful that her county health department brought the shot to her.

“I feel happy that I took it, that way I have access to my grandkids,” the 64-year-old said after receiving the Johnson & Johnson vaccine from a Rutgers University nursing student. “I want to get out, I want to get back into church.”

About a week later and 40 minutes away in Delaware County, 57-year-old Cindy Tribuiani, a grandmother with inoperable lung cancer, got her first Moderna shot at a local community center. Since January, her daughter has set alarms three times a day as reminders to check appointment websites for her mom and dad, who has colon cancer. She got shut out dozens of times from sites in five Pennsylvania counties, and the state’s online tool, YourTurn, only confirmed that they were eligible for a shot that was impossible to find.

“I kept getting these things in my email, ‘It’s YourTurn,’ from the state,” Tribuiani said. “We know it is our turn!”

Plenty of Pennsylvanians have gotten shots — the state ranks above average in percentage of residents with first doses — and many New Jerseyans by turn have been frustrated by the process. But by most measures, New Jersey is ahead of its neighbor when it comes to delivering vaccinations.

New Jersey has a phone hotline for people without internet access; Pennsylvania has a website with limited utility — as Tribuini discovered — that offers only information and no appointments. New Jersey has had mass vaccination sites for months; Pennsylvania is only now planning them.

» READ MORE: The (im)morality of line-jumping to get COVID-19 vaccines

New Jersey is regularly ranked in the top 10 in the nation in dose-use efficiency, with data showing the state typically administers more than 86% of doses received by the government.

The same scale has consistently ranked Pennsylvania in the bottom half of the country, with the commonwealth at times using less than 75% of available doses. The state has matched the national average in terms of overall vaccinations given but remains below the national average in terms of how many people are fully inoculated. This week, the state jumped from 30th to 17th in the nation for the number of people who received first shots.

In both states, deep racial and economic disparities persist when it comes to who is getting vaccinated. And some health experts warn that as states open eligibility to everyone this spring, those gaps will grow.

Some states, such as Ohio, West Virginia, and Mississippi, have already begun opening vaccine eligibility to all adults. In New Jersey, teachers and transit workers became eligible for shots this month, and Gov. Phil Murphy has indicated that offering vaccines to everyone might not be far off.

» READ MORE: Pa. House passes bill to let Philly suburbs run their own mass vaccine clinics, a bipartisan rebuke of the state’s rollout

Yet Pennsylvania is still inoculating residents only in the 1A category —health-care workers, residents over 65, and those with high-risk conditions.

Comparing states is “really a complicated thing,” said Esther Chernak, a physician and director of Drexel University’s Center for Public Health Readiness and Communication. “What works in West Virginia … probably wouldn’t work in Pennsylvania.”

But public health experts say the states that are distributing vaccines more efficiently tend to have a few things in common: a centralized registration system, strong communication between state and local stakeholders, and a diversified network of both vaccine sites and ways of making appointments.

“This is really where a one-government approach — whether it’s federal and state leaders, or state and local leaders, or all of the above — is so important,” said Howard Koh, a public health professor at the Harvard T. H. Chan School of Public Health and the Harvard Kennedy School.

And comparing the experiences of Pennsylvania and New Jersey a year into the pandemic, and more than three months after vaccines became available, illustrates that point.

From the start of the pandemic, the Trump administration made it plain that there would not be a single national response; rather, states were left largely on their own.

Pennsylvania opted to continue that concept, putting counties and health-care providers in charge of everything from gauging vaccine interest, creating wait lists, contacting patients when it’s their turn, scheduling appointments, and giving out shots.

“Providers, not just counties but all providers, including health systems across the state already have an existing relationships with customers, patients, and residents as well as existing registration systems to support the current vaccine rollout,” a Department of Health spokesperson said in a statement. “Additionally, we know that even those states with a centralized system face the same problem — limited vaccine.”

But the state’s approach has changed in recent weeks, with the news that state health officials are now planning at least one mass vaccination site per region, similar to the six state-run “megasites” launched in New Jersey this year. Pennsylvania officials indicated they will run the sites, as well as other sites that use the new Johnson & Johnson single-dose shots.

» READ MORE: The Philly suburbs will get two mass vaccination sites, despite objections from ‘disappointed’ county leaders

“We are using a lot of different channels, and I think we’re having success,” Gov. Tom Wolf said last week at a news conference.

But some counties are pushing back, and House members on Wednesday approved a bill that would let the counties run the mass sites.

» READ MORE: Pa. House passes bill to let Philly suburbs run their own mass vaccine clinics, a bipartisan rebuke of the state’s rollout

Pennsylvania has no hotline where residents without internet access can get on a wait list or schedule appointments — a gap that the Delaware County Council called “the most vexing weakness” for residents and providers.

“This system favors those who have the luxury of spending hours and hours online searching for appointments,” the council said in a statement, “and disadvantages those who don’t have constant access to a computer, broadband access and time to spare.”

A recent Harvard University panel on the vaccine rollout highlighted the experiences in several states. Indiana, which has regularly been distributing about 80% of its allocated vaccines, developed a centralized registration system and website that provided users with an option to choose which brand of vaccine they want, and the ability to search by county or zip code to find a clinic with available doses.

The state also used other ways to reach out to people, said Kristina Box, the state’s health commissioner, including a call center to help make appointments and training at libraries to assist those without internet access.

West Virginia began focusing on concerns about vaccine hesitancy in some communities as early as December, said Ayne Amjad, that state’s health commissioner.

Discovering that some people found the term mass clinic off-putting, “we started using the word community clinic,” she said. “Words do matter when you want to get trust built up.”

New Jersey’s online vaccine registration and scheduling system launched this year, but many residents still have to search for appointments across multiple websites. The state later established a call center, though some calls went unanswered for hours.

Officials have said that the delays stem from overwhelming demand and that the registration system has since allowed them to begin contacting seniors to help them get appointments.

“I don’t know that there was any way to get around the technological challenges that we have and have had,” George Helmy, the governor’s chief of staff, said in an interview. “These were just the hurdles that were always going to be there.”

Connecticut’s health officials have credited good communication with the governor’s office and state health officials, as well as coordination among the state’s hospitals, for its ability to distribute half of its allotted vaccine doses at a time when only about 28% were being used nationally, the Wall Street Journal reported.

The state decided to use age — not profession or health conditions — as the sole condition of eligibility to keep things simple, Gov. Ned Lamont said.

The approach was criticized by some for lacking nuance, but the Hartford Courant reported equity improved. Lamont said this month vaccine should be available to everyone over the age of 16 by April 5, a month earlier than anticipated.

This month, Wolf announced every Pennsylvanian in group 1A — those over 65 or with health conditions — must be scheduled for appointments by the end of March, and get shots before eligibility opens to all adults on May 1. Neither Wolf nor other officials explained how they would achieve that goal in a process that’s been called a “degrading Hunger Games” by some seniors.

» READ MORE: Pa. seniors are ‘at their wit’s ends’ trying to get coronavirus vaccines

Some Pennsylvania residents are finding it easier to cross state lines for a shot. New Jersey officials have acknowledged vaccinating numerous Keystone State residents, and on the west side of the state, people are finding that vaccine sites in Ohio do not always require proof of residency.

Complicating the Pennsylvania picture is the fact that Philadelphia has its own vaccine allocation and its own rules, some of them federally imposed. As a result, suburban cancer patients who get treatment in the city are unable to get vaccinated by their health providers. Philadelphia residents who are younger than 75 had to wait weeks longer than their suburban neighbors to become eligible.

While Pennsylvania reports data on the race of vaccine recipients, the information is too incomplete to know how equitable the distribution is. In Philadelphia, white people are being vaccinated at about twice the rate of Black residents, though whites are a minority of the population.

In New Jersey, close to 60% of doses are going to white residents, according to state data. Last month, the state launched community clinics in cities in an effort to narrow the disparity, and pop-up clinics — like the county-run event that helped Camden resident Marilyn Jackson — have also been rolled out.

That type of layered approach is key, said Chernak, of Drexel University, especially for elderly or homebound people who aren’t able to line up at a clinic.

“The biggest problem in our region is just access,” she said. “We’re not giving it out in ways that are obvious, that are transparent, that are clear.”