The CDC on Nov. 23 corrected Pennsylvania's COVID-19 vaccination data after it had included 1.2 million more doses than were actually administered, The New York Times reports.
It reflects the largest revision of state vaccination figures to date, according to the Times. The vaccination data on the CDC's site, which is updated daily, showed about 84 percent of people in Pennsylvania had received at least their first dose of the vaccine as of Nov. 22. That dropped to 81 percent the following day.
The agency has collaborated with submitting entities and periodically updated states' vaccination data since July 14, according to its site. In all, the CDC and the states have reduced the number of reported doses administered by about 2 million.
Some revisions have also resulted in an increase in a state's number of administered vaccines. Data for Utah, for example, was revised July 14 to add 5,978 administered doses. On Oct. 29, Illinois revised data that resulted in an increase of 316,351 administered doses, though again revised data Nov. 18 that subtracted more than 214,000 doses.
A spokesperson for Pennsylvania's health department told the Times it "continues to update and refine our vaccination data throughout the commonwealth to ensure duplicate vaccination records are removed and dose classification is correct," adding that the CDC had now started to "rectify" the data.
"This is not a practice specific to Pennsylvania and the CDC is going through a similar process with other states across the country," Barry Ciccocioppo with the state's health department said.