CDC-Funded Study of 99 Million COVID-Vaccinated People Finds ‘Very Rare Adverse Events’

A study of adverse events in 99 million people vaccinated for COVID-19 found increased but…

Children's Health Defense

A global study of over 99 million people found increased risks of several serious adverse events following COVID-19 vaccination. However, the researchers concluded the conditions were very rare and the benefits of vaccination still outweigh the risks.

Researchers from the New Zealand-based Global COVID Vaccine Safety project conducted the study, published Feb. 12 in the journal Vaccine, with funding from the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Health and Human Services (HHS).

The observational study pooled data on people who received the Pfizer or Moderna mRNA vaccines or the Oxford AstraZeneca adenovirus vector vaccine across 10 sites in eight countries in Europe, the Americas, Australia and Asia.

Scientists calculated post-vaccination rates of neurological, cardiovascular and other outcomes occurring up to 42 days after the shots and compared them to background rates before the pandemic.

The researchers found increased risks for myocarditis, pericarditis, Guillain-Barré syndrome and cerebral venous sinus thrombosis (CVST), noting these confirmed similar findings in previous research. The study also identified other safety signals of concern.

The analysis had limitations including nonstandard data sources across countries, inability to fully account for risk factors between groups and lack of coverage in some global regions such as the U.S.

According to Brian Hooker, Ph.D., senior director of science and research at Children’s Health Defense, told The Defender, the cutoff date of 42 days is “unrealistic for all of the adverse events considered, especially cardiac conditions which appear primarily after physical exertion.”

Hooker said:

“It is so curious how the issues presented in the ‘results’ section of the paper misaligned with the sunshine-and-roses assurance in the ‘conclusions’ section where the adverse events are referred to as ‘rare’ without any qualifier to define what the authors mean by ‘rare.’”

Key findings ‘likely much worse for susceptible target groups’

The large-scale retrospective study focused on 13 prespecified outcomes judged to be of particular interest for vaccine safety monitoring, including:

Neurological: Guillain-Barré syndrome, transverse myelitis, Bell’s palsy, acute disseminated encephalomyelitis, generalized and febrile seizures.
Hematological: CVST, splanchnic vein thrombosis, thrombocytopenia, immune thrombocytopenia, pulmonary embolism.
Cardiovascular: myocarditis, pericarditis.

The study pulled data from sites in Denmark, France, Canada, Argentina, Australia, Finland, Scotland and New Zealand. Data were collected from vaccinations from December 2020 through August 2023, with some variations between countries.

Researchers found a 2.49 times higher-than-expected occurrence of Guillain-Barré syndrome following the initial dose of the AstraZeneca vaccine.

Cases of CVST, which can lead to strokes, increased by 3.23 times after the first AstraZeneca dose.

Myocarditis and pericarditis risks were significantly elevated after both mRNA vaccines and were seen across the first three doses. The highest risks were after the second Moderna vaccine dose — a 6.1 times increase in risk — and for pericarditis after the third dose of AstraZeneca — a 6.91 times increased risk.

“The OE [observed-to-expected] ratios (over 6.0) for cardiac sequelae just jump off the page and are extremely likely much worse for susceptible target groups, including adolescents, young adults and men,” Hooker said…