No one opened most of the doors Alisha Mays knocked on in North Philadelphia on a recent Saturday.

From each doorknob, she hung a flier with information about nearby places to get a COVID-19 vaccine and who is eligible for shots.

Though focused on a zip code where almost 3,300 people contracted COVID-19 during the pandemic, Mays was careful not to take the lack of interest personally.

“Whatever you choose to do with that information is up to you,” said Mays, a canvasser with Philly Counts, a community engagement unit in the city’s managing director’s office.

At one rowhouse, someone answered, but it wasn’t the person she was looking for. At another address, there was no home at all, just a vacant lot.

More than half of the city, almost 853,000 people, have received at least one vaccine dose, according to data from the Centers for Disease Control and Prevention, including 66% of people age 18 and older. Getting shots to those remaining will be an arduous process of door-to-door interactions and small clinics where success is measured in dozens of vaccines administered, not the thousands given at some sites just a few months ago.

The flow of vaccine doses into arms has reduced to a trickle. From Tuesday to Thursday, days when the city releases updated vaccination information, most zip codes saw vaccinations increase by less than 1%.

“I definitely think it’s the vaccine-hesitant people coming through now,” said Alexandra Pero, a Philadelphia Department of Public Heath staffer running a vaccination clinic in Germantown on Wednesday.

Despite so many Philadelphians still unvaccinated, the impact of the vaccine on the city has been extraordinary. During the first half of June, fewer than 900 new confirmed cases were reported, according to city data. Compare that with the situation just before Thanksgiving, when the total exceeded 1,000 cases in a single day.

Disparities in cases and vaccinations

Across some neighborhoods this summer, vaccines, social distancing and warm weather that allows more outdoor living have made new cases astonishingly rare. In the zip codes that include much of Center City west of Broad Street — home to 30,000 residents — only six confirmed cases were reported during the last 28 days. There was just one so far in June.

Parts of Center City have far exceeded the 70% vaccination rate some health officials have estimated might create herd immunity.

» READ MORE: As COVID-19 vaccination uptake slows, Philly Counts prepares for an outreach surge

Yet in the less affluent, less white zip codes, the situation is starkly different. In several Philadelphia zip codes, less than a third of the residents have been vaccinated.

The result is a steady but uneven recovery:

  • Manayunk has had two confirmed cases since June 1 among its 6,000 residents, about half of whom have had at least one dose of vaccine, according to the city health department data.

  • In the 19147 zip code, which includes Bella Vista and Queen Village, there were 10 new cases among 39,000 residents, of whom nearly two-thirds are at least partially vaccinated.

  • But in the 19121 zip code where Mays knocked on doors, 28 new cases were recorded in the first half of June, the second-highest rate in the city. With about 45% of residents partially or fully vaccinated, that still leaves about 15,000 people unprotected.

“Vaccination rates in African American and Hispanic communities are lower than among whites in every corner of the nation,” said Matthew Rankin, a spokesperson for the city Health Department. “This is not something the Health Department can fix in any short amount of time, which is why our strategy has shifted to more personal, high-touch, one-to-one conversations, to help assuage fears and combat misinformation.”

There’s no one cause of the disparity, and the ranks of the unvaccinated include people wary but potentially willing, as well as the deeply opposed. Poor access to vaccines early in the rollout, poor outreach and information until recently, online misinformation, and decades of disenfranchisement from the health care system among the Black community all contribute.

Philly Counts has focused canvassing efforts — visits, phone calls and text messages — on zip codes that have low vaccination rates and a high prevalence of social factors such as poverty and language barriers. Every home Mays went to where no one came to the door will be visited again, and, if necessary, a third time.

As of June 15, Philly Counts made 95,527 phone calls and knocked on 5,084 doors.

Incentives, convenience, and conversation

Pat West approached the Lonnie Young Rec Center in Germantown on Wednesday afternoon with a plastic bag of medications and a lot of trepidation. There was no line. Just a few dozen people had come to get vaccinated that morning.

“I’m standing here,” the 70-year-old Germantown woman told Alexandra Pero, the Health Department official running the vaccination clinic at the center, “I want to get it but I’m still nervous.”

West had wanted to be vaccinated for a while, she said, but was worried it might interfere with the seven different medications she takes after a triple-bypass in March that put her in the hospital for weeks.

Pero introduced her to Julianne Burns, a doctor on site who explained that the vaccine wouldn’t interact with any of West’s medications. After a long conversation, West walked to one of the vaccination stations on the rec center’s basketball courts.

“I’m much calmer than I was when I arrived,” she said.

Mel Jacob, on the other hand was adamant that she wouldn’t get the vaccine. She was there with her mother, Jennifer Oville, 58, who did get vaccinated. Her mother has diabetes, putting her at higher risk for serious COVID-19 complications.

“If she wants it, I can’t stop her,” Jacob said.

She had safety concerns, she said. “What are they putting in there?” she said. “Radiation? Metal?”

Despite ample evidence that COVID-19 vaccines are safe, conspiracy theories such as the ones Jacob heard persist because they validate deep-seated unease.

“It’s like instinct,” Pero said. “You’re trying to protect yourself.”

She and other health officials don’t argue. They focus on educating and making it easy to get vaccinated at small neighborhood sites, mobile and pop-up clinics, and even micro clinics outside storefronts and libraries.

The city’s shift to smaller clinics in under-vaccinated neighborhoods is a bet that convenient access and ample time to discuss concerns will prove convincing.

“I think people just want to talk it over with a health professional,” Burns said. “They want to know what our experience has been being vaccinated.”

» READ MORE: Philly is trying to bridge vaccine gaps by targeting hard-hit neighborhoods. Finally, activists and experts say.

On Tuesday, the clinic at the Pennsylvania Convention Center offered two Phillies tickets to anyone who got a shot. The result was one of the busiest days at the clinic in weeks, and the 1,000 tickets were all claimed by the end of the day. Hispanic recipients got 30% of the tickets, and 23% went to Black Philadelphians. The Health Department is partnering with Wawa and the city’s professional sports teams to continue offering prizes for people who get the shots. A lottery also allows anyone who gets vaccinated to be eligible for cash prizes from $1,000 to $50,000. The first drawing is to be June 21.

Yet the task of making contact with the roughly 700,000 unvaccinated Philadelphians remains daunting.

West learned about the clinic in her area while reading an article online, and wondered why there wasn’t a more comprehensive effort to drop fliers in neighborhood mailboxes.

“They might have had a bigger turnout,” she said.

Rankin said the city’s health workers may not yet have gotten to her street.

“They have been working through heavily impacted and underserved neighborhoods as quickly as they can.” Rankin said.

Graphics editor John Duchneskie contributed to this article.