Pfizer’s COVID-19 vaccine has been linked to blood clotting in older people, according to the US Food and Drug Administration (FDA).
The FDA researchers, analyzing data from a database of older people in the United States, found that pulmonary embolism (blood clots in the lungs) met the baseline threshold for a statistical signal and continued to meet criteria after further evaluation. deeper.
Three other outcomes of interest — lack of oxygen to the heart, a blood platelet disorder called immune thrombocytopenia, and another type of clotting called intravascular coagulation — initially raised red flags, the researchers said. Further evaluations, such as comparisons with populations that received influenza vaccines, showed that those three no longer met the statistical threshold for a signal.
The researchers analyzed data from 17.4 million older Americans who received a total of 34.6 million doses of vaccines between December 10, 2020, and January 16, 2022.
The study was published by the vaccine magazine on December 1.
The FDA said it would not take any action on the results because they do not prove that the vaccines cause any of the four outcomes, and because the findings “are still under investigation and require more robust study.”
Dr. Peter McCullough, chief medical adviser for the Truth for Health Foundation, told The Epoch Times via email that the new article “substantiates physicians’ concerns that the large increase in blood clots, the progression of atherosclerotic heart disease and blood disorders are independent factors associated with vaccination against COVID-19.”
Pfizer did not respond to a request for comment.
How the research was done
FDA investigators, with the assistance of investigators from the Centers for Medicare & Medicaid Services (CMS), analyzed data from the CMS database. They included fee-for-service Medicare recipients age 65 and older who received a vaccine on time, were enrolled when vaccinated, and were enrolled during a “clean period” of time before vaccination. The window was 183 or 365 days, depending on the result.
About 25 million people receive fee-for-service Medicare, but only about 17 million were vaccinated during the time period studied.
The researchers used probability tests to detect increased risk for one or more of 14 outcomes after vaccination. The goal was to see if vaccination might increase the risk of adverse outcomes, such as pulmonary embolism or blood clots in the lungs. If an outcome met a certain statistical threshold, that meant it might increase risk.
Initial safety monitoring results detected an increased risk of four events, the FDA announced on July 12, 2021. They were the same four described in the new document, which is the first update the agency has given on the matter since its announcement.
As of January 15, 2022, 9,065 cases of oxygen deprivation to the heart, known as acute myocardial infarction, have been detected, the researchers revealed in the new study. On the same date, 6,346 cases of pulmonary embolism, 1,064 cases of immune thrombocytopenia, and 263 cases of coagulation were detected.
The primary analysis showed a safety signal for all four outcomes. The researchers tried to adjust the numbers using different variables. For example, at one point they adjusted for the change in background rates, or the rates of each outcome in the general population before the pandemic. After some adjustments, but not all, myocardial infarction, immune thrombocytopenia, and intravascular coagulation were no longer statistically significant.
However, pulmonary embolism remained statistically significant, the researchers said. Pulmonary embolism is a serious condition that can lead to death.
Study limitations included potential false signals and potential missed signals due to factors such as incorrect parameter specification.
Conditions that did not trigger a signal included stroke, heart inflammation, and appendicitis.
Signals were detected only after vaccination with Pfizer. Signal analyzes after receiving the Moderna and Johnson & Johnson vaccines did not show any concerns.
Moderna and Johnson & Johnson did not respond to requests for comment.
Side effects
All three vaccines have been linked to a number of side effects. Heart inflammation is causally linked to injections from Moderna and Pfizer, experts around the world have confirmed, while Johnson & Johnson has been linked to blood clots.
Other conditions, such as pulmonary embolism, have been reported to authorities and described in studieshowever some papers have not found an increased risk after vaccination.
Approximately 4,214 reports of post-vaccination pulmonary embolism, including 1,886 reports following receipt of the Pfizer vaccine, were reported to the US Vaccine Adverse Event Reporting System as of December 9.
As of the same date, 1,434 reports of post-vaccination myocardial infarction, including 736 after receiving the Pfizer vaccine; 469 reports of post-vaccination immune thrombocytopenia, including 234 post-reception of the Pfizer vaccine; and 78 reports of post-vaccination intravascular coagulation, including 42 after receiving the Pfizer vaccine.
Anyone can make reports to the system, but most are submitted by health workers, studies show. The number of reports is an undercount, according to the studies.
The new study states that the FDA “strongly believes that the potential benefits of vaccination against COVID-19 outweigh the potential risks of COVID-19 infection.” No evidence was cited in support of the belief.
The FDA will meet with its vaccine advisory panel in January 2023 on the future of COVID-19 vaccines, as the vaccines have performed much worse against Omicron and its subvariants.
McCullough told The Epoch Times: “A shortcoming of the CMS surveillance system is that it failed to capture both pre- and post-SARS-CoV-2 infection, accentuating the cumulative risk of COVID-19 vaccination. Given the large number of people who have been vaccinated, the population-attributable fraction of medical problems attributed to vaccines is enormous. I have concerns about the future. burden on the health system as a consequence of massive and indiscriminate vaccination against COVID-19”.
Zachary Stieber is a senior reporter for The Epoch Times based in Maryland. He covers news from the United States and the world.
