Studies and Research
The body of research on the effects of intramuscular injections is vast and detailed. However, the highly technical language in these studies can be difficult for the general public to understand.
In public health research, authors often soften their wording due to pressure from journals to downplay negative findings on side effects and adverse reactions. As a result, important insights are frequently obscured or carefully phrased in the papers themselves—though they remain visible in the data sets and discussion sections upon close review.
To address this, HFDF has created this searchable compendium of studies, each paired with clear, plain-language summaries and notes prepared by our team. Our goal is to cut through technical complexity, bias, and ambiguity so individuals can access the key facts and make informed health decisions.
This resource will continue to grow, with new studies and improvements added regularly.
Please note that HFDF does not necessarily endorse or support any policy arguments or specific assumptions made by the authors. HFDF commentary describes and summarizes the role this study plays in the scientific discourse and provides abbreviated notes.
Recently Posted Studies
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Epidemiology of Myocarditis and Pericarditis Following mRNA Vaccination by Vaccine Product, Schedule, and Interdose Interval Among Adolescents and Adults in Ontario, Canada
Notes higher rates of heart damage in young males, 3 days post vaccination. Urges caution and to consider timing to reduce such damage.
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Persistent cardiac magnetic resonance imaging findings in a chohort of adolescents with post-coronavirus disease 2019 and mRNA vaccine myopericarditis
Heart abnormalities in teens post-vaccination persisted for months.
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Increased cardiovascular events among under-40 population in Israel during vaccine rollout and third COVID-19 wave.
For adults over 40, emergency calls for cardiac arrest and ACS during vaccination period, but no difference from 2019 to 2020. for younger people, calls increased by 25% during vaccine rollout. inference is that covid Vaccination signficantly increases the risk of severe heart damage
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Applying spectral analysis to the arterial pulse to discriminate cardiovascular side effects following administration of Moderna’s mRNA-1273 vaccine
Journal: European Journal of PharmacologyLead Author:
Chao, et al.Original date of publication:
11/01/2025Technical study on particularly tough to detect arterial stiffness that few would report to VAERS or doctors in general. Specifically focsed on Moderna vaccine.
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Real world effectiveness of antipneumococcal vaccination against pneumonia in adults: a population-based cohort study, Catalonia, 2019
This study looked at over 2 million residents of Catalonia, Spain, and found not only no benefit from pneumococcal vaccination, but even higher rates of pneumonia.
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Incidence of Respiratory Infections after the COVID-19 Pandemic (2023–2024) and Its Association of Vaccination Among Entire Populations in Korea
Lead Author:
Song, et al.Original date of publication:
11/01/2025With each additional COVID-19 “vaccine” received, the higher risk of developing common cold and upper-respiratory infections, even TB








