Southeastern Pennsylvania lawmakers said they were angry and frustrated Thursday after state health officials abruptly rescheduled a planned call to discuss the region’s vaccine supply, leaving the legislators and their constituents still asking how many more shots are coming.

The Pennsylvania Department of Health said it was investigating how much the Philadelphia suburbs may have been shortchanged in the rollout of the coronavirus vaccine. Over the weekend, an Inquirer data analysis revealed the suburban Philadelphia counties were receiving fewer doses per capita than other, less populous counties.

Lawmakers on Thursday said they had been seeking answers from the state for weeks with little response. They questioned why the Health Department needed more time to analyze its own data.

“If the Department of Health doesn’t have this data, doesn’t have this analysis already, who does?” said State Sen. Maria Collett. “You tell them where to send the doses ... so this shouldn’t be new information to you that Montgomery County, Chester County, Delaware County, Bucks County are coming up short. It’s unfortunate to me that there is still sort of a real lack of direct response and what I think is a lack of accountability.”

On Monday, state officials acknowledged the undersupply to members of Pennsylvania’s congressional delegation and said Delaware County would be getting a boost in doses. But the Health Department declined to provide information to reporters Wednesday about whether the other counties’ allocations would increase, then canceled Thursday’s meeting with lawmakers and county officials, citing the need to do more data analysis.

As of Thursday, Montgomery, Chester, and Bucks Counties had gotten even fewer doses per resident this week than a week ago, according to a new Inquirer analysis, while Delaware County remained low-ranked but got more doses this week than last.

“We rescheduled the call to make sure our analysis could be as robust as possible before holding the call with the delegation,” acting Health Secretary Alison Beam said at a Thursday news conference.

» READ MORE: Pennsylvania admits vaccine undersupply in Philadelphia suburbs, promises to fix it with extra doses immediately | Maria Panaritis

For lawmakers and residents around the region, the cancellation was another disappointment in a vaccine rollout that has fully or partially inoculated more than 1.7 million Pennsylvanians but has drawn criticism for confusion, communication stumbles, and the patchwork system in place for finding shots. In mid-February, miscommunications between the state and providers caused a vaccine shortage that delayed thousands of shots.

The federal government allocates doses to Pennsylvania weekly. The state’s counties and providers send requests for doses each week to the Department of Health, which then uses a formula to allocate them based on the state’s supply.

Bucks County Republicans introduced a bill Thursday to require vaccine doses to be distributed to counties based on population, citing The Inquirer analysis. The Health Department’s current formula for determining how many vaccines each county gets uses other factors in addition to population, including the senior population, the number of coronavirus cases and deaths, and the virus positivity rate.

“We cannot get a straight answer on how the formula for distributing the vaccine was crafted,” the seven lawmakers said in a joint statement. “Now we are left to force responsible actions by the state’s Department of Health by mandating it through statute.”

The Department of Health is “very much interested in providing full transparency,” spokesperson Barry Ciccocioppo said in a statement to The Inquirer. “In order to do that we are thoroughly analyzing the myriad of data necessary to provide a full picture of the vaccine flow. We will be meeting with local leaders in the next few days to share that information.”

Asked about the allocation issue on a telephone town hall with Rep. Madeleine Dean (D., Montgomery and Berks) on Thursday evening, Beam cited the state’s formula, saying allocations aren’t determined by population alone and said some rural counties receive larger shipments because their hospitals supply multiple locations. She also said the rate of vaccine administration in the Philadelphia suburbs is on par with the state average.

“We’ve had a lot of conversations about that this week,” Beam said of the supply question. “We’re going to be sharing some information as soon as this weekend with county leadership to remind folks of the process that we go through.”

Lawmakers have been asking for Southeastern Pennsylvania-specific meetings for weeks, said State Rep. Jennifer O’Mara, who represents Delaware County and is chair of the House Democratic Caucus’ Southeast Delegation.

Both Republicans and Democrats from the region had been “excited” for Thursday’s virtual gathering, O’Mara said, because “we were hoping they’d be forced to answer our questions they had kind of been ignoring.”

State Rep. Mike Zabel, a Delaware County Democrat, said lawmakers had received mixed messages from the department and questioned why officials had acknowledged the undersupply to members of Pennsylvania’s congressional delegation but told state lawmakers they needed more time to review data.

“This isn’t just some territorial competition — this is a matter of, for some people, life or death,” Zabel said. “If mistakes were made, so be it; let’s correct that by compensating for the deficit and making sure the problem is fixed going forward.”

Collett, a Democrat who represents Bucks and Montgomery Counties, said lawmakers had heard the Southeastern Pennsylvania call was set to be rescheduled for Sunday. She said Democratic state senators asked questions of Beam at a caucus meeting the secretary attended Thursday afternoon.

“People were really frustrated about accountability, about how did we get here and why is the Department of Health still telling us that they need to do more analysis of numbers?” Collett said.

County leaders in Bucks, Montgomery, and Chester have said their Health Departments are being underutilized and could be vaccinating many more people. Officials have asked not only for an equitable allotment of doses but also for more doses to be sent to providers, like the counties, that can hold mass vaccination clinics, said Chester County Commissioner Josh Maxwell.

“We were hoping to hear improvements from the Department of Health on equitable distribution of vaccines in Southeastern Pennsylvania and disappointed that we didn’t get that today,” Maxwell said. “We’ve sent letters, our state representatives have sent letters, our congresswomen have sent letters — now we’re just looking for the problem to be fixed.”

State Rep. Meghan Schroeder, a Bucks County Republican, called the commonwealth’s vaccine distribution process “a nightmare.”

“The vaccine was not something that just ‘popped up’ — we knew it was coming, there is no excuse for not being prepared,” she said. “We want answers. Our constituents want answers. And now we will have to wait even longer to try to get them.”

Graphics editor John Duchneskie contributed to this article.