Data shows that those four counties received far fewer doses of the vaccine than many smaller counties across the commonwealth.
According to the latest state data analyzed by 6abc, per every 1,000 residents, Delaware County (564,554 residents) has received 134 doses, Bucks County (626,806 residents) received 168 doses, Chester County (519,560 residents) received 171 doses and Montgomery County (823,823 residents) received 221 doses.
By comparison, the state reports having sent almost 45,000 doses to Montour County over the last three months. The county's population is only 18,259 people.
Four other smaller counties, Mifflin, Mercer, Clarion and Elk all received more than 500 doses for every 1,000 of their residents, according to state data.
Out of 67 counties, Delaware County is ranked 46th in the state.
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"I think that's very concerning," said Deandra Taylor of Yeadon.
"That doesn't make any sense. I mean I would think we'd be prioritized," said Jason Avalone of Springfield, Delaware County.
"It's extremely frustrating. The taxes out here are exorbitant and you would think that we would be able to get better services," said Shama Albany of Yeadon.
"Why are we toward the bottom of the list? I'd really like to know that one because I'd get the vaccine if I could," said Gene Kelly of Collingdale.
Emails to the Pennsylvania Department of Health and Delaware County Council seeking comment were not answered.
A former Republican member of the county council was outraged.
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"I couldn't even imagine and I wouldn't even guess how potentially this could have an affect on the senior citizens that haven't been able to get a vaccine out because we're not getting our fair share," said Culp.
The data does not include Philadelphia County, which administers its own vaccine distribution directly with the federal government.