The Centers for Disease Control and Prevention (CDC) has updated Pennsylvania's COVID-19 vaccination data after finding that about 1.2 million more doses had been recorded than the state has actually administered.
This revision brings the state's vaccination rate down from 84 percent of Pennsylvanians with at least one Covid shot to 81 percent.
While the CDC periodically revises vaccination numbers and other Covid data in order to provide the most accurate information to Americans, this revision is the largest of state vaccination figures thus far.
Accurate vaccination numbers are crucial for public health leaders to make informed recommendations about Covid safety, experts say.
The CDC revised Pennsylvania's count of vaccine doses administered, leading to a drop in the state's vaccination rate. Pictured: A Pittsburgh, Pennsylvania resident receives her second dose of the Moderna vaccine at a public clinic, April 2021
About 15 million vaccine doses have been administered in Pennsylvania, according to the state's dashboard. The CDC's tally is higher (18 million) as it includes doses administered through federal programs, such as pharmacy partnerships
Almost 70 percent of Americans have received at least one dose of a Covid vaccine, according to the CDC, as of November 23.
This includes 74 percent of the eligible population - all adults and children ages 5 and up. It also includes 82 percent of adults and almost 100 percent of seniors.
More than 36 million Americans have received booster shots since the additional doses were first authorized for immunocompromised people in August.
While the number of people in the U.S. inoculated against the coronavirus has risen steadily throughout 2021, the CDC and other health agencies occasionally revise numbers up or down after researchers identify errors in the data.
For example, in July, the governor of Utah issued an apology, explaining that his office had announced 70 percent of adults had received at least one COVID-19 vaccine before this benchmark was actually hit.
In fact, 67 percent of Utah residents were vaccinated at the time.
Utah's error occurred due to an issue with counting doses administered in Utah by federal agencies, including pharmacy partnerships and Indian Health Services.
Another common source of vaccination data inaccuracy is double-counting: the same person may be included in vaccination records twice, due to a misspelled name or a similar error.
Such a mistake led to a recent CDC revision of vaccination data for Pennsylvania.
On Tuesday, the agency revised Pennsylvania's count of vaccine doses administered down by about 1.2 million doses from about 19.1 million doses to 18 million.
This is higher than the Pennsylvania health department's figure of about 15 million doses, likely
