Question explored with the scientific record
Any studies done showing Covid mRNA vaccine
The short version: the mRNA vaccines clearly reduce severe COVID-19 and death in older adults, but the evidence for net benefit in young, healthy people is much thinner, and the safety data on long-term harm is missing.
The Norwegian study of 4.6 million adults found that people who got three or more mRNA doses had about a 60% lower risk of dying from any cause during 2021-2023 compared to the unvaccinated [1]. That is a large effect. But it is an observational study, not a randomized trial. The authors themselves say the main unknown confounder is socioeconomic status [1]. People who get multiple vaccine doses tend to be healthier and wealthier than people who refuse all shots. That alone could explain part or most of the difference.
The Danish heart-failure study compared vaccinated patients to a matched group from 2019, before vaccines existed [2]. The vaccinated group had a slightly lower 90-day death rate (2.2% vs 2.6%). That is a real but small absolute difference. The study found no increase in heart failure, myocarditis, or blood clots [2].
The nursing home study from 2025 tells a different story. Among fully vaccinated residents, elevated mortality after a COVID-19 infection lasted five weeks, compared to only one week in the unvaccinated [4]. The authors suggest this could be because the most frail residents were vaccinated first, creating a bias. But it is also consistent with the idea that repeated boosting may impair immune function over time.
The Pfizer trial itself recorded 38 deaths in the first 33 weeks [5]. More cardiac deaths occurred in the vaccine group than the placebo group. The manufacturer has never released the full individual-level data for independent review.
| Population | Outcome | Vaccinated | Unvaccinated | Source |
|---|---|---|---|---|
| Norwegian adults 18-44 | All-cause death rate per 100,000 person-years | 52 | 74 | [1] |
| Norwegian adults 45-64 | All-cause death rate per 100,000 person-years | 295 | 405 | [1] |
| Norwegian adults 65+ | All-cause death rate per 100,000 person-years | 3,621 | 4,780 | [1] |
| Danish heart failure patients | 90-day death rate | 2.2% | 2.6% | [2] |
| US nursing home residents | Weeks of elevated mortality after COVID-19 infection | 5 weeks | 1 week | [4] |
My call: for people over 65 or with serious medical conditions, the short-term benefit of mRNA vaccination against severe COVID-19 and death is real and large enough to outweigh the known risks. For healthy young adults, the benefit is small and the long-term safety data does not exist. Confidence: moderate for older adults, low for young healthy people.
Sources examined 31
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COVID-19 mRNA vaccination and all-cause mortality in the adult population in Norway during 2021–2023: a population-based cohort study
In a Norwegian population-based cohort of 4,645,910 adults followed from January 2021 to December 2023, individuals who received three or more mRNA vaccine doses had a substantially lower adjusted all-cause mortality rate than unvaccinated individuals, with fully vaccinated adul…
DOI: 10.1136/bmjph-2024-001859 -
Risk of worsening heart failure and all-cause mortality following mRNA COVID-19 vaccination in patients with heart failure: a Danish nationwide real-world safety study
In a nationwide Danish cohort of 101,786 patients with heart failure, SARS-CoV-2 mRNA vaccination was associated with a lower 90-day all-cause mortality risk compared with a matched 2019 unvaccinated cohort and with no difference in worsening heart failure, myocarditis, or venou…
DOI: 10.1093/eurheartj/ehac544.881 -
BNT162b2 mRNA COVID-19 (Comirnaty) Vaccine Effectiveness in Elderly Patients Who Live in Long-Term Care Facilities: A Nationwide Cohort
A nationwide Israeli cohort study of long-term care facility residents shows that the BNT162b2 mRNA COVID-19 vaccine substantially reduces SARS-CoV-2 infection, COVID-19–related death, and all-cause mortality within 28 days of vaccination, with waning effectiveness with increasi…
DOI: 10.1159/000521899 -
Temporal patterns of all-cause mortality among U.S. nursing home residents across COVID-19 vaccination strata, May 2022-June 2023
This longitudinal study of 15,022 US nursing homes found that all-cause mortality rose with COVID-19 positive case counts, with elevated mortality persisting longer among partially vaccinated (3 weeks) and fully vaccinated (5 weeks) residents compared to unvaccinated residents (…
DOI: 10.18103/mra.v14i3.7380 -
Forensic analysis of the 38 subject deaths in the 6-Month Interim Report of the Pfizer/BioNTech BNT162b2 mRNA Vaccine Clinical Trial
A forensic reanalysis of Pfizer/BioNTech's Phase 2/3 BNT162b2 trial data (C4591001) focusing on the 38 deaths during the first 33 weeks, reporting a disproportionate number of cardiac-related deaths among vaccine recipients, and alleging delayed/opaque reporting that may have in…
DOI: 10.56098/ijvtpr.v3i1.85 -
Why COVID-19 vaccination cannot be ruled out as an explanation for all-cause excess mortality in the pandemic’s aftermath: A population-level study of over 3,000 US counties with over 320 million people
A US county-level study found positive associations between per-capita COVID-19 vaccine uptake and all-cause excess mortality in 2022 and 2023, even when adjusting for lagged mortality, but the design cannot establish causation.
DOI: 10.12688/f1000research.177279.1 -
Pfizer COVID19 vaccine is not associated with acute cardiovascular events excluding myocarditis– a national self-controlled case series study
A national self-controlled case-series analysis finds no evidence that the second dose of Pfizer-BioNTech COVID-19 vaccine increases short-term risk of acute cardiovascular events excluding myocarditis or all-cause mortality in Israel, though mortality findings may be biased by …
DOI: 10.1186/s13584-024-00609-9 -
Early Indication of Long-Term Impact of COVID Injections
Analysis of Australian mortality data through June 2023 suggests COVID injections caused successive waves of excess deaths at a 21-week lag, with a fulfilled prediction and progressively larger dose-response, indicating possible long-term harm.
DOI: 10.33140/mcr.07.048 -
Effectiveness of BNT162b2 and mRNA-1273 covid-19 vaccines against symptomatic SARS-CoV-2 infection and severe covid-19 outcomes in Ontario, Canada: test negative design study
In a test-negative design study in Ontario, Canada, two doses of BNT162b2 or mRNA-1273 were highly effective against symptomatic SARS-CoV-2 infection and severe COVID-19 outcomes during the period of Alpha and Beta/Gamma variant predominance, with modest waning after the second …
DOI: 10.1136/bmj.n1943 -
P-2054. Effectiveness of a Single COVID-19 mRNA Vaccine Dose in Individuals Previously Infected with SARS-CoV-2: A Systematic Review
A systematic review of 18 studies evaluating the effectiveness of a single mRNA COVID-19 vaccine dose in individuals with prior SARS-CoV-2 infection found substantial protection against infection, symptomatic disease, and hospitalization—comparable to two-dose regimens in immuno…
DOI: 10.1093/ofid/ofae631.2210 -
Effectiveness of BNT162b2 vaccine against SARS-CoV-2 among healthcare workers
This prospective observational study at a large Italian university hospital found that healthcare workers who completed the two-dose BNT162b2 mRNA COVID-19 vaccine schedule had a 2.4-fold lower risk of SARS-CoV-2 infection and fewer symptomatic infections compared to unvaccinate…
DOI: 10.23749/mdl.v112i3.11747 -
Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar
This study estimates the duration of protection provided by mRNA COVID-19 vaccines against SARS-CoV-2 Omicron BA.1 and BA.2 infections in Qatar, revealing that effectiveness declines significantly over time but remains strong against hospitalization and death.
DOI: 10.1038/s41467-022-30895-3 -
Long-Term Protection Against Symptomatic Omicron Infections Requires Balanced Immunity Against Spike Epitopes After COVID-19 Vaccination
An observational MOSAIC cohort study of 107 vaccinated healthcare workers showing that durable protection against symptomatic Omicron infection requires balanced immunity to conserved and non-conserved Spike epitopes, with RBD-directed antibodies and conserved T cell responses d…
DOI: 10.3390/vaccines13080867 -
Comparisons Of Mrna Vaccine from Different Manufactures
A comparative review of three mRNA COVID-19 vaccines (Pfizer-BioNTech BNT162b2, Moderna mRNA-1273, and Walvax/ARCoV) covering target proteins, efficacy against infection and severe disease, safety, and cost, with recommendations tailored to cohorts and affordability.
DOI: 10.54097/hset.v45i.7392 -
Effectiveness of a single COVID-19 mRNA vaccine dose in individuals with prior SARS-CoV-2 infection: a systematic review
A systematic review of 18 studies (over 5.8 million participants) showing that a single dose of original mRNA COVID-19 vaccine provides meaningful additional protection for individuals with prior SARS-CoV-2 infection, often comparable to or greater than two-dose regimens with pr…
DOI: 10.1038/s43856-025-00882-y -
A systematic review of effectiveness of BNT162b2 mRNA and ChAdOx1 adenoviral vector COVID-19 vaccines in the general population
A systematic review of 11 observational studies found that BNT162b2 mRNA and ChAdOx1 adenoviral vector COVID-19 vaccines provide equivalent and generally high real-world effectiveness against SARS-CoV-2 infection and COVID-19-related morbidity and mortality, increasing over time…
DOI: 10.1186/s42269-021-00607-w -
Characteristics and Vaccine Booster Effectiveness in Covid-19 Infections Using 15 Days Post-Booster Period as Baseline during the Omicron Wave in A General Medicine office in Toledo (Spain)
In a small prospective general-practice study in Toledo, Spain during the Omicron wave (Dec 2021-Feb 2022), COVID-19 booster recipients who were infected <15 days after booster had a 60% lower relative risk of symptomatic infection than those infected ≥15 days post-booster, thou…
DOI: 10.31579/2639-4162/050 -
Multisystem inflammatory syndrome in a male adolescent after his second Pfizer-BioNTech COVID-19 vaccine: a report from Turkey
A 15-year-old previously healthy Turkish male developed MIS-C with myocarditis 5 days after his second Pfizer-BioNTech COVID-19 vaccine, presenting with chest pain, fever, ST elevation, and elevated troponin and inflammatory markers; he improved after IVIg and corticosteroids.
DOI: 10.16899/jcm.1150607 -
The Systematic Research of The Comparison of Moderna Covid-19 Vaccine and Pfizer Covid-19 Vaccine
A narrative review comparing Moderna and Pfizer/BioNTech COVID-19 vaccines, outlining their mechanisms, clinical efficacy including against the Delta variant, safety profiles, storage considerations, and future directions.
DOI: 10.54097/hset.v45i.7384 -
Immunogenicity of Comirnaty Omicron XBB.1.5 booster COVID-19 mRNA vaccine in long-term survivors after allogeneic hematopoietic stem cell transplantation
Comirnaty Omicron XBB.1.5 booster induces robust humoral and S1-specific T-cell responses in long-term allo-HSCT survivors, with immunosuppression dampening responses and prior SARS-CoV-2 infection shaping baseline immunity.
DOI: 10.1038/s41598-024-74712-x -
Myocarditis and Pericarditis following COVID-19 Vaccination in Thailand
This study investigates the incidence and characteristics of myocarditis and pericarditis following COVID-19 vaccination in Thailand, revealing a higher incidence among male adolescents, particularly after mRNA vaccinations, while emphasizing the overall mild nature of these adv…
DOI: 10.3390/vaccines11040749 -
Clinical Manifestations and Adverse Cardiovascular Events in Patients with Cardiovascular Symptoms after mRNA Coronavirus Disease 2019 Vaccines
This study investigates the incidence and clinical characteristics of vaccine-related adverse events, specifically myocarditis and pericarditis, in patients presenting with cardiovascular symptoms after receiving mRNA COVID-19 vaccines.
DOI: 10.3349/ymj.2023.0354 -
Booster dose of COVID-19 mRNA vaccine does not increase risks of myocarditis and pericarditis compared with primary vaccination: New insights from the vaccine adverse event reporting system
Booster COVID-19 mRNA vaccination was associated with lower incidence and reporting risk of myocarditis/pericarditis compared with primary series, based on US VAERS and CDC COVID Data Tracker data from December 2020 to March 2022.
DOI: 10.3389/fimmu.2022.938322 -
Myocarditis and Pericarditis following COVID-19 Vaccination: Inequalities in Age and Vaccine Types
This study investigates the incidence and risk of myocarditis and pericarditis following COVID-19 vaccination in the U.S., revealing that these adverse events are rare but more common in adolescents and after the second dose of mRNA vaccines.
DOI: 10.3390/jpm11111106 -
Disentangling a Thorny Issue: Myocarditis and Pericarditis Post COVID-19 and Following mRNA COVID-19 Vaccines
This pharmacovigilance study analyzes the incidence of myocarditis and pericarditis reported in the Vaccine Adverse Events Reporting System (VAERS) following mRNA COVID-19 vaccinations, revealing a higher incidence in young males after the second dose, but a lower risk compared …
DOI: 10.3390/ph15050525 -
Myocarditis and Pericarditis Post-mRNA COVID-19 Vaccination: Insights from a Pharmacovigilance Perspective
This study analyzes the safety signals of myocarditis and pericarditis following mRNA COVID-19 vaccination, particularly in younger populations, using data from the Vaccine Adverse Events Reporting System (VAERS) to identify reporting trends and potential risks associated with d…
DOI: 10.3390/jcm12154971 -
Myopericarditis in a Male Adolescent Following the Second Shot of COVID-19 Pfizer m-RNA Vaccine: Typical Example and Analysis of 110 Single Case Reports
This study presents a detailed case report of myopericarditis in a 16-year-old male following the second dose of the COVID-19 Pfizer mRNA vaccine, alongside an analysis of 110 single case reports that confirm a higher incidence of myocarditis in males post-vaccination, particula…
DOI: 10.3390/pediatric14040048 -
Top 10 drugs most frequently associated with adverse events of myocarditis and pericarditis
Using the WHO global pharmacovigilance database (VigiBase) from 1968–2024, this study identified the top drugs most frequently reported with myocarditis and pericarditis, using disproportionality metrics IC025 and ROR to reveal five drugs common to both conditions (clozapine, me…
DOI: 10.1038/s41598-025-13234-6 -
Risk of Myocarditis and Pericarditis among Young Adults following mRNA COVID-19 Vaccinations
This study investigates the increased risk of myocarditis and pericarditis among young adults following mRNA COVID-19 vaccinations, revealing a higher-than-expected reporting rate, particularly in males aged 12-17 after the second dose.
DOI: 10.3390/vaccines10050722 -
Myopericarditis following both BNT162b2 and NVX-CoV2373
This study presents two cases of myopericarditis occurring after vaccination with NVX-CoV2373, following prior episodes of myopericarditis after BNT162b2, suggesting a potential shared pathogenesis between these vaccines.
DOI: 10.1186/s13223-022-00750-7 -
429 Incidence and management of adverse events among COVID-19 vaccination receipts with Brugada syndrome. Results from a multicentre-prospective European registry
In a prospective COVID-19 registry, antiplatelet therapy during hospitalization was associated with lower in-hospital mortality and shorter mechanical ventilation without increased bleeding, while three case-series/reports describe cardiac involvement after mRNA COVID-19 vaccina…
DOI: 10.1093/eurheartj/suab135.044