The miraculous COVID vaccine protects against cardiovascular events. Here’s why this study is biased

Cai M, Xie Y, Al-Aly Z. 2024–2025 COVID-19 Vaccine and Major Adverse Cardiovascular Events Among U.S. Veterans. JAMA Intern Med. Published online June 15, 2026. jamanetwork.com/journal…

This study is based on data from U.S. Army veterans, which is kept secret and is inaccessible to independent scientists who might wish to replicate the study; the authors work for the U.S. Army.

Here’s why this study is biased.

It is a comparison between those who received only the flu vaccine and those who received both the flu vaccine and the COVID-19 vaccine on the same day. Therefore, it is not a comparison between vaccinated and unvaccinated individuals. Rather, it compares cardiovascular adverse events resulting from a COVID-19 infection among vaccinated and “unvaccinated” individuals.

I put “unvaccinated” in quotes because this group includes people who may have received the COVID-19 vaccine after the flu vaccine.

Those who experienced cardiovascular adverse events following a COVID-19 vaccine received shortly afterward (most often 1 to 2 months later) are classified as UNVACCINATED.

The authors do not explain how those who had a COVID-19 infection are counted: is it a symptomatic infection? A positive COVID-19 test? It seems quite obvious that those who received the COVID-19 vaccine will likely be classified as “COVID-19 infected” less often than those who are truly unvaccinated against COVID-19 (those who did not receive the COVID-19 vaccine after the flu vaccine). It has been shown that vaccinated individuals are less likely to undergo PCR testing than unvaccinated individuals. This completely invalidates the study’s results.

8,800 participants were excluded because they tested positive for the flu or COVID-19 within 90 days prior to enrollment. This excludes the risks associated with COVID-19 vaccination following a COVID-19 infection: it has been shown that this leads to additional risks of adverse effects.

Data from the supplementary material.

The “healthy vaccinated” bias was not avoided despite the authors’ claims. In fact, Table 3 in the supplement shows that those who did not receive both vaccines on the same day are in poorer health than the other participants classified as “vaccinated.” They are at higher risk for cardiovascular, cerebrovascular, renal, and pulmonary diseases, as well as diabetes, and they are more often immunocompromised.

There is a higher risk of death from the flu in the “unvaccinated” group. A death or adverse event due to the flu means that the patient tested positive for the flu. It is not specified whether the “vaccinated” group is tested for the flu and COVID-19 in an equivalent manner; this invalidates the results because a death or adverse event could be randomly associated with the flu or COVID-19 if testing is not equivalent.

Figure 6 in the supplement shows that adverse events are higher among the “vaccinated” group in the first month following concurrent vaccination, particularly cardiovascular deaths associated with a COVID-19 infection—including myocardial infarctions (MI) and strokes—as well as cardiac arrests associated with a COVID-19 infection.

The study’s calculations are based on 8-month results. It is known that cardiac events following COVID-19 vaccines occur primarily in the days following vaccination. Therefore, the comparison should have been made over a 1-month follow-up period between the “unvaccinated” and the vaccinated. Based on the provided curves, it is likely that the result would have been unfavorable to the COVID-19 vaccine.