A 15-year-old receives a first dose of the Pfizer Covid-19 vaccine at a mobile vaccination clinic at the Weingart East Los Angeles YMCA on May 14, 2021 in Los Angeles, California. - The campaign to immunize America's 17 million adolescents aged 12-to-15 kicked off in full force on May 13. The YMCA of Metropolitan Los Angeles is working to overcome vaccine hesitancy and expand access in high risk communities with community vaccine clinics in the area. (Photo by Patrick T. FALLON / AFP) (Photo by PATRICK T. FALLON/AFP via Getty Images)

By Zachary Stieber

The U.S. Centers for Disease Control and Prevention (CDC) is saying it has performed vaccine safety data mining and analyses since early 2021, a reversal from a recent letter.

The CDC said in an operating procedures document dated Jan. 29, 2021, that it “will perform” a type of data mining analysis of vaccine safety data called Proportional Reporting Ratio (PRR).

The public health agency also said it would conduct routine surveillance of the data, which is being logged into the Vaccine Adverse Event Reporting System.

The data mining and surveillance were aimed at detecting adverse events occurring at higher-than-expected rates.

But little of what the agency said it would perform has actually been performed, according to a June 16 letter to the Children’s Health Defense, a nonprofit.

The group had asked, in a Freedom of Information Act request, for all data generated in connection with the data mining, as well as copies of other data.

In response, CDC records officer Roger Andoh said that staff within the CDC’s Immunization and Safety Office “inform me that no PRRS were conducted by CDC.”

“Furthermore, data mining is outside of th[e] agency’s purview; staff suggest you inquire with the FDA,” or the U.S. Food and Drug Administration, he wrote.

The FDA was tasked with conducting a different method of data mining, according to the procedures document.

The CDC also failed to produce other information it said it would be producing, such as weekly tables of all reports of adverse events following COVID-19 vaccines.


The reaction to the disclosure was swift. Joshua Guetzkow, a senior lecturer in the Department of Sociology and Anthropology at The Hebrew University of Jerusalem who has been applying his training in statistics to examine vaccine safety, said it showed the CDC “lied” about its efforts to monitor the safety database, known as VAERS.

“In their own document on their own website, they state unambiguously what their plans were to monitor VAERS for safety signals. They failed to do that,” Guetzkow, who has been working with Children’s Health Defense, told The Epoch Times via email.

“Another thing: in their FOIA response, they said that data mining is outside the CDC’s purview. Then why did they say they were going to do data mining with PRRs in the SOP briefing document?” he wondered.

Sen. Ron Johnson (R-Wis.), who has been attempting to get answers from federal agencies throughout the pandemic, told CDC Director Rochelle Walensky in a letter that the disclosure “raises questions about whether CDC ever collected the information on vaccine safety it originally claimed it would” in the operating procedures document.

The request for information that triggered the CDC’s response was for data from Feb. 1, 2021, through Sept. 30, 2021.

Dr. John Su, of the CDC’s Immunization and Safety Office, heads the CDC’s VAERS team, which authored the operating procedures.

“CDC has been performing PRRs since Feb 2021, and continues to do so to date,” Su told The Epoch Times via email.

Hope That CDC Is ‘More Forthcoming’

In its response to the Freedom of Information Act request, the CDC “was unequivocal: the agency said it hasn’t done PRR and has no responsibility to do so,” Risa Evans, with Children’s Health Defense (CHD), told The Epoch Times in an email.

“Now the CDC states that it has in fact been conducting PRR since February 2021. CHD will certainly follow up with the CDC to obtain those records, and hopefully, the agency will be more forthcoming this time around in light of its legal obligations under FOIA and its stated commitment to ‘openness and accountability,’” she added.

The Epoch Times has filed a Freedom of Information Act (FOIA) request for all PRR analyses the CDC has conducted, as well as other information. The VAERS team told The Epoch Times that the information “will be provided to you,” though a date has not been given.

The FDA, meanwhile, says that it has conducted a different type of analysis, called Empirical Bayesian data mining.

“FDA does perform Empirical Bayesian data mining periodically on data from VAERS as part of its vaccine safety monitoring efforts,” a spokesperson told The Epoch Times in an email.

Asked for the results, the spokesperson did not respond.

The Epoch Times has filed a FOIA request with the FDA for the results.

Guetzkow in 2021 performed his own analysis of data from VAERS. That analysis uncovered safety signals for a number of events, including severe allergic shock, Bell’s palsy, heart inflammation, and stroke. Some of the events have been confirmed to be connected, or described as likely connected, to one or more of the COVID-19 vaccines by the CDC and other U.S. authorities.

“CDC and FDA have been actively engaged in vaccine safety surveillance ever since COVID-19 vaccines have been in use. During the first month of their availability, data on anaphylaxis after [the Pfizer and Moderna] COVID-19 vaccines were published (including in highly visible journals, like the Journal of the American Medical Association (JAMA), indicating an observed incidence comparable to data after other vaccines. VAERS detected what would become known as thrombosis with thrombocytopenia syndrome (TTS) after Janssen’s vaccine, leading to a pause in the use of the vaccine mere weeks after its use was initiated. VAERS reviewed reports of myocarditis after mRNA COVID-19 vaccines during Summer 2021, providing a highly thorough characterization of such reports,” Martha Sharan, a spokeswoman for the CDC, told The Epoch Times in an email.

“These examples indicate that the vaccine safety surveillance systems in use by CDC and FDA identify potential vaccine safety concerns in a timely and effective manner.”

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