John Murphy, CEO The COVID Long haul Foundation<\/p>\n\n\n\n
An evidence-based assessment of mortality, morbidity, reproductive outcomes and the question of longer-term effects<\/strong><\/p>\n\n\n\n The United States has now accumulated more than five years of post-authorization experience with COVID-19 vaccines. Hundreds of millions of Americans have received one or more doses, generating an unusually large body of safety data from the Centers for Disease Control and Prevention, the Food and Drug Administration, the National Institutes of Health, the Department of Defense and other surveillance systems.<\/p>\n\n\n\n The central question is no longer simply whether adverse events occur after vaccination. They do.<\/p>\n\n\n\n The more difficult questions are which events are causally associated with vaccination, how frequently they occur, how long they persist, whether repeated doses alter risk, and whether any health consequences could emerge only after years rather than weeks or months.<\/strong><\/p>\n\n\n\n The available evidence permits some of those questions to be answered. Others remain unresolved.<\/p>\n\n\n\n That distinction is particularly important when discussing cancer, infertility, miscarriage, autoimmune disease and mortality. There is currently no reliable scientific basis for assigning a future incidence or \u201cpeak year\u201d to such outcomes when a causal relationship has not been established.<\/p>\n\n\n\n The federal government operates multiple complementary vaccine-safety systems.<\/p>\n\n\n\n VAERS is a passive reporting system jointly administered by CDC and FDA. It accepts reports of health events occurring after vaccination whether or not the reporter believes the vaccine caused the event. CDC explicitly cautions that VAERS reports alone cannot establish causation.<\/p>\n\n\n\n The Vaccine Safety Datalink uses linked electronic health records from participating health systems and permits comparison of vaccinated and unvaccinated populations.<\/p>\n\n\n\n The Department of Defense maintains additional systems, including the Defense Medical Surveillance System, military electronic health records and the Vaccine Adverse Event Clinical System. CDC describes these systems as part of the federal post-authorization safety network.<\/p>\n\n\n\n The National Institutes of Health and National Cancer Institute support additional epidemiological and biological research.<\/p>\n\n\n\n These systems are fundamentally different from one another. A VAERS report is a signal; an epidemiological association is stronger evidence; and a replicated association accompanied by biological and clinical evidence can establish causality.<\/p>\n\n\n\n Among the potential harms investigated since 2020, myocarditis following mRNA COVID vaccination has the strongest evidence of causality.<\/p>\n\n\n\n CDC states that evidence from multiple U.S. and international safety-monitoring systems supports a causal relationship between mRNA COVID-19 vaccines and myocarditis and pericarditis. Cases occur most frequently in adolescent and young adult males, particularly within seven days after the second mRNA dose.<\/p>\n\n\n\n The National Academies reached the same conclusion in its 2024 comprehensive evidence review: the evidence establishes a causal relationship between both Pfizer-BioNTech’s and Moderna’s vaccines and myocarditis.<\/p>\n\n\n\n This finding has an important long-term dimension.<\/p>\n\n\n\n The immediate event is acute inflammation of the heart. The longer-term question is whether some individuals experience persistent myocardial injury, fibrosis, arrhythmia or other cardiac consequences.<\/p>\n\n\n\n Those outcomes require longitudinal follow-up rather than simply counting acute VAERS reports.<\/p>\n\n\n\n CDC therefore specifically identifies the need to investigate the long-term effects of vaccine-associated myocarditis.<\/p>\n\n\n\n The Johnson & Johnson\/Janssen adenoviral-vector vaccine produced two important safety signals that were not characteristic of the mRNA vaccines to the same degree.<\/p>\n\n\n\n The first was thrombosis with thrombocytopenia syndrome, or TTS.<\/p>\n\n\n\n CDC estimates approximately four cases per million Janssen doses and concluded that a causal relationship exists.<\/p>\n\n\n\n The second was Guillain-Barr\u00e9 syndrome.<\/p>\n\n\n\n CDC’s analyses found an increased risk of GBS following Janssen vaccination but not following Pfizer-BioNTech or Moderna vaccination.<\/p>\n\n\n\n The National Academies likewise concluded that the evidence favors acceptance of causal relationships between Janssen vaccination and both TTS and GBS.<\/p>\n\n\n\n The Janssen product therefore demonstrates why COVID vaccines cannot appropriately be treated as one biological exposure. Vaccine platform matters.<\/p>\n\n\n\n Neurological conditions have generated substantial reports and research interest, including:<\/p>\n\n\n\n The important distinction is between reported events and demonstrated vaccine causation<\/strong>.<\/p>\n\n\n\n The 2024 National Academies review found that evidence favored rejecting causal relationships between the mRNA vaccines and GBS and Bell’s palsy. For many other neurological conditions, however, the evidence was insufficient either to establish or reject causation.<\/p>\n\n\n\n That does not establish that vaccines cause those disorders. It means that the available evidence was insufficient for a definitive causal conclusion.<\/p>\n\n\n\n Thrombotic events have been extensively investigated.<\/p>\n\n\n\n The National Academies found evidence favoring rejection of causal relationships between the mRNA vaccines and myocardial infarction and, for Pfizer-BioNTech, ischemic stroke. For pulmonary embolism and some other thromboembolic outcomes, the evidence was more complicated and, in some cases, inadequate to accept or reject causation.<\/p>\n\n\n\n CDC’s Vaccine Safety Datalink nevertheless identified a statistical signal for ischemic stroke during the 2023\u201324 season among some age and vaccine groups. CDC reported that cumulative evidence did not provide clear and consistent evidence of a safety problem and initiated additional analysis.<\/p>\n\n\n\n The distinction is consequential:<\/p>\n\n\n\n A statistical signal is a reason to investigate\u2014not proof of causation.<\/strong><\/p>\n\n\n\n Acute kidney injury has appeared in post-vaccination reports and has been examined in military and civilian data.<\/p>\n\n\n\n A Department of Defense review of cardiac and kidney outcomes found that VAERS reports of acute kidney injury were concentrated disproportionately among older individuals with comorbidities such as diabetes, hypertension and heart disease. Most reported cases developed within two weeks of vaccination, and the review noted that many had alternative explanations such as volume depletion or sepsis.<\/p>\n\n\n\n The same report noted that most kidney dysfunction described in two systematic reviews returned toward baseline within approximately 90 days.<\/p>\n\n\n\n The available evidence therefore does not establish a population-wide chronic kidney injury syndrome caused by COVID vaccination.<\/p>\n\n\n\n Miscarriage has been one of the most frequently discussed potential adverse outcomes.<\/p>\n\n\n\n VAERS contains reports of pregnancy loss following vaccination, but a VAERS report does not establish causation.<\/p>\n\n\n\n More informative studies have compared pregnancy outcomes among vaccinated and unvaccinated women.<\/p>\n\n\n\n CDC’s pregnancy surveillance has found no increased risk of miscarriage, preterm delivery, stillbirth or birth defects associated with COVID vaccination. CDC currently states that more than one million pregnant women worldwide have received mRNA COVID vaccines and that studies have not demonstrated increased risks of these outcomes.<\/p>\n\n\n\n A systematic review likewise concluded that available evidence does not show an association between COVID vaccination and increased miscarriage risk.<\/p>\n\n\n\n The National Academies also found evidence favoring rejection of a causal relationship between the two mRNA vaccines and female infertility.<\/p>\n\n\n\n Thus, miscarriage is an important outcome to monitor, but the available comparative evidence does not<\/strong> demonstrate that COVID vaccination increases miscarriage.<\/p>\n\n\n\n Menstrual changes provide a different example.<\/p>\n\n\n\n Numerous women reported alterations in menstrual timing or bleeding following vaccination. Subsequent research has detected small, generally temporary changes in cycle length.<\/p>\n\n\n\n A recent systematic review and meta-analysis found a small increase in menstrual-cycle length following vaccination, with the effect generally confined to the first cycle.<\/p>\n\n\n\n CDC’s own vaccine-safety case studies now identify menstrual irregularities as an adverse-event concern that emerged through postmarketing surveillance and public reporting.<\/p>\n\n\n\n The available evidence therefore supports distinguishing temporary menstrual disturbance<\/strong> from infertility or permanent reproductive impairment.<\/p>\n\n\n\n Female infertility was specifically reviewed by the National Academies.<\/p>\n\n\n\n For Pfizer-BioNTech and Moderna, the evidence favored rejection of a causal relationship with female infertility.<\/p>\n\n\n\n The available evidence therefore does not support projecting a future population-wide infertility epidemic caused by mRNA COVID vaccination.<\/p>\n\n\n\n That conclusion does not mean every reproductive question has been answered. It means that the specific hypothesis of increased female infertility has not been supported by the evidence reviewed to date.<\/p>\n\n\n\n Deaths following vaccination have been reported to VAERS.<\/p>\n\n\n\n But death following vaccination is not equivalent to death caused by vaccination.<\/p>\n\n\n\n This distinction is particularly important because federal reporting requirements can require a death to be reported even when the cause is uncertain. CDC notes that VAERS is designed to capture adverse events occurring after vaccination and that reports may be submitted when causation is unclear.<\/p>\n\n\n\n Therefore, a simple calculation of VAERS deaths cannot establish vaccine-attributable mortality.<\/p>\n\n\n\n Determining whether vaccination increased mortality requires comparison with expected background mortality, appropriate controls, adjustment for age and medical conditions, and ideally replication in independent databases.<\/p>\n\n\n\n The military health system has attracted particular attention because its databases contain longitudinal medical information on a relatively well-defined population.<\/p>\n\n\n\n Claims concerning dramatic increases in numerous medical diagnoses following COVID vaccination were made from Defense Medical Epidemiology Database data.<\/p>\n\n\n\n The Department of Defense subsequently conducted formal analyses using the Defense Medical Surveillance System and related military medical databases. Its published report examined cardiac and kidney outcomes using military medical records and immunization information rather than relying solely on raw DMED counts.<\/p>\n\n\n\n The lesson from the military data is methodological: raw database changes cannot automatically be interpreted as vaccine effects.<\/p>\n\n\n\n Changes in diagnostic coding, healthcare utilization, surveillance practices, deployment patterns, population composition and data completeness can all affect apparent disease rates.<\/p>\n\n\n\n The appropriate question is whether an observed increase remains after those factors are controlled.<\/p>\n\n\n\n Cancer is perhaps the most consequential long-term question because cancer may take years to develop and therefore cannot be evaluated adequately using only the first one or two years after vaccination.<\/p>\n\n\n\n There is currently no established evidence that COVID-19 vaccines cause cancer<\/strong>.<\/p>\n\n\n\n The National Cancer Institute states that there is no evidence that COVID-19 vaccines cause cancer, cause recurrence or make cancer more aggressive.<\/p>\n\n\n\n That finding is important, but it does not mean that cancer surveillance should cease.<\/p>\n\n\n\n Cancer epidemiology requires long observation periods. Many cancers develop over years, and changes in incidence can result from aging, environmental exposure, screening practices, obesity, smoking, infection, treatment advances and many other variables.<\/p>\n\n\n\n Consequently, it is scientifically inappropriate to assign a future \u201cpeak\u201d in vaccine-associated cancer without evidence demonstrating that vaccination increases cancer risk in the first place.<\/p>\n\n\n\n A credible signal would require several findings occurring together:<\/p>\n\n\n\n At present, those criteria have not been satisfied for COVID vaccines.<\/p>\n\n\n\n Therefore, a projection that COVID vaccination will produce a future cancer peak would be speculative rather than a finding of the available databases.<\/p>\n\n\n\n This is a legitimate epidemiological question, but it has to be framed correctly.<\/p>\n\n\n\n Vaccines can produce adverse effects that appear after vaccination, and some immune-mediated events may have consequences extending beyond the initial inflammatory response.<\/p>\n\n\n\n For established COVID-vaccine adverse effects, the timing is generally much shorter than years.<\/p>\n\n\n\n For myocarditis, CDC identifies the highest-risk period as approximately the first week following vaccination.<\/p>\n\n\n\n For Janssen-associated TTS and GBS, the recognized risk periods were similarly concentrated in the weeks following vaccination.<\/p>\n\n\n\n CDC’s broader vaccine guidance states that serious adverse events generally occur within six weeks of vaccination.<\/p>\n\n\n\n This does not prove that every conceivable consequence must occur within six weeks. It does establish that the known vaccine-associated safety signals have characteristic temporal patterns that are generally measured in days or weeks rather than many years.<\/p>\n\n\n\n The available evidence supports dividing possible long-term outcomes into three categories.<\/p>\n\n\n\n The table illustrates an important point: the absence of evidence for a future harm is not equivalent to proof that the future harm is impossible.<\/strong><\/p>\n\n\n\n But the reverse is equally important.<\/p>\n\n\n\n The existence of a theoretical possibility is not evidence that the harm will occur.<\/strong><\/p>\n\n\n\n The most comprehensive independent U.S. review to date was conducted by the National Academies of Sciences, Engineering, and Medicine.<\/p>\n\n\n\n The committee reviewed hundreds of studies and produced 85 conclusions concerning possible harms. For 20 relationships it found sufficient evidence to make a causal determination; for 65 relationships the evidence was insufficient to accept or reject causation.<\/p>\n\n\n\n For the mRNA vaccines, the evidence established myocarditis as a causal adverse effect.<\/p>\n\n\n\n The evidence favored rejecting causal relationships with GBS, Bell’s palsy, TTS, myocardial infarction and female infertility, with Pfizer-BioNTech also having evidence favoring rejection of an association with ischemic stroke.<\/p>\n\n\n\n For many other outcomes, including several neurological, vascular and auditory conditions, the committee found the evidence insufficient to establish or reject causation.<\/p>\n\n\n\n This is perhaps the most useful description of the current state of knowledge.<\/p>\n\n\n\n The CDC, NIH, FDA and Department of Defense databases provide extensive information about adverse events occurring after vaccination.<\/p>\n\n\n\n They establish several important safety findings.<\/p>\n\n\n\n They do not<\/strong>, however, provide a scientifically defensible basis for predicting that COVID vaccination will produce a future wave of cancer, infertility, miscarriage or premature mortality.<\/p>\n\n\n\n A future cancer peak cannot be calculated without a demonstrated excess cancer risk.<\/p>\n\n\n\n A future infertility peak cannot be calculated without evidence of an increased infertility rate.<\/p>\n\n\n\n A future mortality peak cannot be calculated from VAERS reports because VAERS does not establish cause of death.<\/p>\n\n\n\n The appropriate scientific approach is continued longitudinal surveillance.<\/p>\n\n\n\n Several questions remain worthy of continued study:<\/p>\n\n\n\n These are empirical questions.<\/p>\n\n\n\n They require large linked databases, appropriate control groups, standardized diagnostic criteria and many years of follow-up.<\/p>\n\n\n\n More than five years of COVID-vaccine experience has produced enough evidence to identify several genuine adverse events.<\/p>\n\n\n\n The strongest established causal association for the mRNA vaccines is myocarditis. Janssen vaccination was causally associated with TTS and GBS. Menstrual changes have been observed, generally as temporary disturbances. Numerous other conditions have been investigated, but evidence for causation remains insufficient or favors rejection of an association.<\/p>\n\n\n\n For pregnancy, current evidence does not demonstrate increased miscarriage, stillbirth, preterm birth or congenital abnormalities following COVID vaccination.<\/p>\n\n\n\n For cancer, the National Cancer Institute reports no evidence that COVID vaccines cause cancer, recurrence or progression.<\/p>\n\n\n\n For mortality, VAERS cannot distinguish deaths caused by vaccination from deaths that happened after vaccination.<\/p>\n\n\n\n The most important unresolved issue is therefore not whether additional surveillance is necessary. It is what additional surveillance can establish that current surveillance cannot<\/strong>.<\/p>\n\n\n\n Cancer, infertility, reproductive loss and overall mortality should continue to be monitored over sufficiently long periods. But projections of future peaks in these outcomes should not be presented as established findings unless population-level evidence demonstrates an excess risk.<\/p>\n\n\n\n The available federal evidence supports a more precise conclusion:<\/p>\n\n\n\n COVID-19 vaccines have identifiable adverse effects, some of which are causally established; many other alleged harms remain unproven or have evidence against causation; and the available data do not currently establish a long-term cancer, infertility, miscarriage or mortality syndrome attributable to COVID vaccination.<\/strong><\/p>\n\n\n\n That is the state of the evidence as of 2026.<\/p>\n","protected":false},"excerpt":{"rendered":" John Murphy, CEO The COVID Long haul Foundation An evidence-based assessment of mortality, morbidity, reproductive outcomes and the question of longer-term effects The United States has now accumulated more than […]<\/p>\n","protected":false},"author":2,"featured_media":15898,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[978,761,939,1362,974,607,608,609],"tags":[],"class_list":["post-15867","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-adverse-event-reporting","category-concerns","category-safety-studies","category-vaccine-deaths","category-vaccine-long-term-safety","category-vaccine-news","category-vaccine-safety","category-vaers"],"_links":{"self":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/15867","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15867"}],"version-history":[{"count":3,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/15867\/revisions"}],"predecessor-version":[{"id":15870,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/15867\/revisions\/15870"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/media\/15898"}],"wp:attachment":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15867"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15867"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15867"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}What the federal safety systems actually contain<\/h5>\n\n\n\n
The strongest established safety signal: myocarditis<\/h5>\n\n\n\n
The Janssen vaccine produced a different safety profile<\/h5>\n\n\n\n
Neurological outcomes remain an area of surveillance<\/h5>\n\n\n\n
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Blood clots, stroke and heart attack<\/h5>\n\n\n\n
Kidney injury<\/h5>\n\n\n\n
Reproductive health and miscarriage<\/h5>\n\n\n\n
Menstrual changes<\/h5>\n\n\n\n
Fertility<\/h5>\n\n\n\n
Mortality<\/h5>\n\n\n\n
What happened with the Department of Defense data?<\/h5>\n\n\n\n
The cancer question<\/h5>\n\n\n\n
What would constitute evidence of a vaccine-associated cancer effect?<\/h5>\n\n\n\n
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Could an adverse effect appear years later?<\/h5>\n\n\n\n
A useful framework for future surveillance<\/h5>\n\n\n\n
Outcome<\/th> Current evidence<\/th> Appropriate surveillance horizon<\/th><\/tr> Myocarditis\/pericarditis<\/td> Causal association established for mRNA vaccines<\/td> Days \u2192 years for cardiac sequelae<\/td><\/tr> TTS<\/td> Causal association with Janssen<\/td> Days \u2192 weeks<\/td><\/tr> GBS<\/td> Causal association with Janssen<\/td> Days \u2192 weeks; longer follow-up for disability<\/td><\/tr> Severe allergic reactions<\/td> Established rare adverse event<\/td> Minutes \u2192 days<\/td><\/tr> Menstrual changes<\/td> Small, generally temporary association<\/td> Weeks \u2192 months<\/td><\/tr> Miscarriage<\/td> Increased risk<\/td> Pregnancy-specific surveillance<\/td><\/tr> Female infertility<\/td> Causal relationship rejected for mRNA vaccines<\/td> Longitudinal reproductive surveillance<\/td><\/tr> Heart attack<\/td> Causal relationship rejected for mRNA vaccines<\/td> Ongoing population surveillance<\/td><\/tr> Ischemic stroke<\/td> No clear consistent causal evidence<\/td> Ongoing surveillance<\/td><\/tr> Pulmonary embolism\/DVT<\/td> Evidence varies by vaccine\/outcome<\/td> Ongoing surveillance<\/td><\/tr> Chronic neurological disease<\/td> Evidence insufficient for several conditions<\/td> Years<\/td><\/tr> Cancer<\/td> No demonstrated causal relationship<\/td> Multi-year population surveillance<\/td><\/tr> Overall mortality<\/td> VAERS reports cannot establish causation<\/td> Long-term epidemiological surveillance<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n What the National Academies found<\/h5>\n\n\n\n
What the databases can\u2014and cannot\u2014tell us about the future<\/h5>\n\n\n\n
The unresolved questions<\/h5>\n\n\n\n
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Conclusion<\/h5>\n\n\n\n