Liany Arroyo, the director of the Hartford Health Department, spends a lot of her time studying neighborhoods in Hartford and finding patterns in their vaccination rates. The downtown areas of Hartford and those that lie to the west of the city show higher vaccination rates in general. Other neighborhoods have sharply lower rates. "The West End is a more affluent neighborhood," Arroyo said. "There's a dividing line there." That dividing line is present in urban areas across the state, and struggles to get vaccines across it are bedeviling public health officials. Despite being prioritized for vaccine administration, Connecticut's cities have consistently lagged behind in the state's vaccine rollout, and detailed data on the neighborhood level show that disparities mirror existing inequities, particularly socioeconomic ones. In an effort to to bolster equity, the state is distributing $13 million in federal funding to 27 local health departments. Local health officials - in conjunction with nonprofit and hospital partners - are using the money and the granular neighborhood data to fine-tune outreach in ZIP codes that the state has designated as priorities. Some are also looking past the state's prioritization system to focus on other hard-hit communities that are currently lagging in vaccination rates, even if they aren't on the state's priority list, such as parts of Bloomfield or Stratford. What's driving vaccine disparities? The Centers for Disease Control and Prevention's "social vulnerability index" has formed the basis for the state's prioritization system and has been a reliable indicator of low vaccine uptake. Generally speaking, the higher a community's SVI score, the lower its vaccination rate, a CT Mirror analysis found. An estimated 32 percent of the state's eligible population lives in the state's priority ZIP codes, and the state aims to administer the same percentage of vaccines within those communities. While the state inches closer to that goal each week, the statewide slowdown in the number of shots administered means that it has a lot of ground to make up. Of all the vaccines administered so far, just 25 percent of all vaccines distributed as of last week have gone to residents of those ZIP codes. "Progress is slower now," said Josh Geballe, the state's chief operating officer, at a recent press conference. Of the 15 different variables that determine a Census tract's vulnerability score, a CT Mirror analysis found that socioeconomic factors considered by the index - namely income, employment status, poverty level and education - were found to be most predictive of vaccination rates. This is consistent with a national study on the county level that the CDC released in March. "Why is this?" asked Yale statistician Charla Nich, who was involved in a door-knocking campaign in March and April called Vaccinate Fair Haven. "And then you think about things like access." Local health directors were divided on whether low uptake rates are a product of access barriers or vaccine hesitancy in their communities - or both. "It's a combination," Arroyo said. "When you think about access to information, to technology and resources, that obviously makes a difference," she said. On the other hand, she believes the pause in the administration of the Johnson & Johnson vaccine dampened demand for vaccination more generally. Hartford is also grappling with the challenge of trying to vaccinate a population that skews younger, Arroyo said. Vaccine behavior is a spectrum - and it isn't useful to group people into just two camps of enthusiastic and hesitant, said Saad Omer, a Yale epidemiologist who serves on The Lancet's Commission on Vaccine Refusal and testified before Congress on building vaccine confidence last week. In between, there are people who exhibit "passive acceptance," who are open to most vaccines but aren't seeking them out; there are also those who come to embrace some vaccines over time. Kica Matos, vice president for initiatives at the Vera Institute for Justice, helped lead the Vaccinate Fair Haven campaign. "Active resistance was few and far between in our efforts," she said. Data from the Kaiser Family Foundation suggest that 15 percent of Americans are open to getting vaccinated but would prefer to wait. Around 13 percent of Americans say that they would refuse vaccination, and another 6 percent say that they would do so only if required to do so. Hispanics were twice as likely as white people to desire vaccination, but Black and Hispanic Americans were more likely to be concerned about missing work as a result of the shot. What are health officials doing about it? Where local health directors do converge is on their strategies to improve the numbers - door-knocking, amplifying vaccine endorsements from trusted community leaders and running pop-up clinics in neighborhoods that show low vaccination rates. For Arroyo, the $1,500,000 grant the she expects to receive will continue the canvassing she has started in Hartford's North End. She also hopes to make vaccination more of community affair by partnering with cultural institutions like the Puerto Rican Day Parade. "We find that doing things in conjunction with events is helpful to get to some individuals that we might not be getting to otherwise," she said. "It also just creates more of a fun atmosphere." Health officials are using the grant money to look beyond the state's priority ZIP codes as well. Bloomfield - a predominantly Black community that has had one of the highest per-capita death rates in the state in non-congregate settings - does not technically score high enough on the SVI to make the state's list of 50 priority ZIP codes. Aimee Krauss, the director of the West Hartford-Bloomfield, does have two priority ZIP codes in her district in West Hartford, which show some of the highest vaccine coverage rates in the state. She applied for and was awarded a $150,000 grant to focus on the eastern part of Bloomfield off of Blue Hills Avenue, which lags in vaccination rates. "The Census tract area that has the lowest vaccination rate is a lower-income area," said Megan Westcott, the West Hartford-Bloomfield Health Department's epidemiologist. In the district's first attempt to canvass there, community health workers had 70 conversations. Seven of those resulted in vaccinations. Local resident Theodore Green has adopted a wait-and-watch approach before deciding to put a vaccine in his arm; the Johnson & Johnson pause made him nervous, but Green was still open to being vaccinated. "I just haven't gotten around to do it yet, but I probably will," Green said. "I'm not one of these guys who thinks it's like getting a bad cold." The dividing line appears in other urban areas. Parts of Stratford that border Bridgeport show much lower coverage rates than others in local health director Andrea Boissevain's charge - and they aren't in priority ZIP codes either. The Stratford Health Department has also been awarded $80,000 in health equity funds, which Boissevain is using for pop-up clinics in the area, including one in a neighborhood school. "The Franklin school is right there, right on the border of Bridgeport," she said. "That's where English as a second language is a higher percentage." The grant also requires local health departments to partner with community-based organizations to plan clinics. "The South End Community Center suggested that we try and go to the Dollar Store, or Walmart, on a day when folks get their SNAP benefits, because people will be there," Boissevain said. "They are folks that we want to make sure have access, when we give them ample opportunity," she added. Under FEMA's terms, grant recipients are required to spend the money by the end of August. "We're going to keep at this fall, summer .. as long as it takes," Geballe said at a press conference last week. Though the state is among the nation's leaders in its vaccination rate and its COVID metrics continue to trend in a positive direction, pockets of the state that report low vaccination rates remain susceptible to COVID outbreaks. "People don't want to talk about herd immunity, because we don't know exactly how to define that, but certainly as the proportion of the population that gets vaccinated increases and our case rates come down, the risk of COVID spreading in our communities is reduced," said Jennifer Kertanis, health director of the Farmington Valley Health District. The vaccination rate data uses population estimates released by the American Community Survey, which contains sampling errors. As a result, the percentage figures are, by definition, approximations. "We are releasing this imperfect data in response to a pressing public health need," said Maura Fitzgerald, DPH spokesperson. "We suggest the data are used primarily to identify areas that need additional attention rather than to establish and track the exact level of vaccine coverage," DPH said in a statement.