The top U.S. public health agency identified hundreds of safety signals for the Pfizer and Moderna COVID-19 vaccines months earlier than previously known, according to files obtained by The Epoch Times.
The U.S. Centers for Disease Control and Prevention (CDC) found more than 700 signals that the vaccines could cause adverse events—including acute heart failure and death—in May 2022, the files show.
The analysis went over reports lodged between Dec. 14, 2020, and May 6, 2022.
When the first analyses were done that month, CDC employees identified more than 200 signals for Pfizer's shot and 93 signals for Moderna's vaccine, the files show. Those analyses compare the events lodged after receiving one vaccine with events lodged after receiving another, or several others.
The Epoch Times obtained the files through Freedom of Information Act requests.
The strongest analysis involves comparing the reports lodged after vaccination with the Pfizer and Moderna COVID-19 vaccines with the reports lodged after vaccination with all non-COVID-19 vaccines. The analysis is contained in files labeled "Table 5."
According to the files provided by the CDC, the agency didn't start that analysis until May 2022.
"The program staff advises that 'Table 5 was only created from May 6, 2022, to July 31, 2022,'" a CDC Freedom of Information Act processer told The Epoch Times via email.
The CDC didn't respond to a request for more information.
Operating ProceduresThe CDC and the U.S. Food and Drug Administration (FDA) co-manage the Vaccine Adverse Event Reporting System, which accepts reports from anybody but is primarily used by health care workers. Reports to the system are analyzed and verified by health officials and contractors.
PRR triggers a signal when three thresholds are met, according to the CDC: a reporting ratio of at least two, a chi-squared statistic (an indicator of the relationship between variables) of at least four, and three or more cases of the event following receipt of the vaccine or vaccines being analyzed. Health officials say that it takes more evidence than signals to establish causality.
The agencies have portrayed the Empirical Bayesian (EB) mining as stronger. Officials have said that the CDC undertook PRR "to corroborate the results of EB data mining."
"PRR results were generally consistent with EB data mining, revealing no additional unexpected safety signals. Given it is a more robust data mining technique, CDC will continue relying upon EB data mining at this time," a CDC spokesperson previously told The Epoch Times.
Probability 'Essentially Zero'Norman Fenton, a professor of risk management at Queen Mary University of London, has reviewed the signals.
Fenton said that for many of the reported adverse events, the chi-squared was so high that the chance that "the true rate of the [adverse events] of the COVID vaccines is not higher than that of the non-COVID vaccines is essentially zero."
He added, "The onus is on the regulators to come up with some other causal explanation for this difference if they wish to claim that the probability a COVID vaccine [adverse event] results in death is not significantly higher than that of other vaccines."