{"id":9773,"date":"2024-08-05T06:55:11","date_gmt":"2024-08-05T10:55:11","guid":{"rendered":"https:\/\/cov19longhaulfoundation.org\/?p=9773"},"modified":"2024-08-05T06:55:11","modified_gmt":"2024-08-05T10:55:11","slug":"study-largely-confirms-known-rare-covid-19-vaccine-side-effects","status":"publish","type":"post","link":"https:\/\/cov19longhaulfoundation.org\/?p=9773","title":{"rendered":"Study Largely Confirms Known, Rare COVID-19 Vaccine Side Effects"},"content":{"rendered":"\n

By\u00a0Kate Yandell<\/a>, 2024, SciCheck Digest<\/p>\n\n\n\n

An international study of around 99 million people confirmed known serious side effects of COVID-19 vaccination. It also identified a possible relationship between the first dose of the Moderna vaccine and a small risk of a neurological condition. Social media posts about the study left out information on the vaccines\u2019 benefits and the rarity of the side effects.<\/p>\n\n\n\n

How safe are the COVID-19 vaccines?<\/p>\n\n\n\n

\n\n\n\n

COVID-19 vaccines \u2014 like all\u00a0vaccines<\/a>\u00a0and other medical products \u2014 come with side effects, including\u00a0serious side effects<\/a>\u00a0in rare cases. The vaccines were rolled out to protect people from a novel virus that has\u00a0killed<\/a>\u00a0millions of people globally and would likely have killed millions more without the arrival of the vaccines. There is a broad consensus from\u00a0experts<\/a>\u00a0and\u00a0governmental<\/a>\u00a0health\u00a0agencies<\/a>\u00a0that the benefits of COVID-19 vaccination outweigh the risks.<\/p>\n\n\n\n

Researchers have\u00a0scrutinized<\/a>\u00a0the COVID-19 vaccines\u2019 safety and continue to do so. A\u00a0study<\/a>\u00a0published Feb. 12 in the journal Vaccine reported on an international group of more than 99 million people who received COVID-19 vaccines, primarily finding links to known rare side effects. The study largely focused on the Pfizer\/BioNTech and Moderna vaccines, which have been\u00a0widely given<\/a>\u00a0in the U.S., as well as the AstraZeneca vaccine, which was\u00a0never authorized<\/a>\u00a0in the U.S.<\/p>\n\n\n\n

\u201cWhat we take away, is that the Covid-19 vaccination campaigns have been very effective in preventing severe disease,\u201d study co-author Anders Hviid<\/a>, head of the department of epidemiology research at the Statens Serum Institut in Denmark, told us in an email. \u201cThe few serious side effects that we have observed in this and other studies have been rare.\u201d<\/p>\n\n\n\n

Many popular posts on social media have shared results from the study, some lacking the context that the identified health problems<\/a> are rare<\/a>, that most<\/a> aren\u2019t new<\/a> and that the vaccines have proven benefits. Various posts made unfounded claims, stating or implying that people should not<\/a> have received<\/a> the vaccines<\/a>, that the risks outweigh<\/a> the benefits or that the risk<\/a> of the rare side effects is greater<\/a> than was reported in the study.<\/p>\n\n\n\n

\u201cHundreds of millions of people were used as lab rats and now the truth that WE ALL ALREADY KNEW can no longer be denied,\u201d said one popular post<\/a>, referring to the vaccines as \u201cexperimental\u201d and \u201cUNTESTED.\u201d The post shared a screenshot of the headline of a New York Post article<\/a> about the new study, which read, \u201cCOVID vaccines linked to slight increases in heart, brain, blood disorders: study.\u201d<\/p>\n\n\n\n

\u201cThis thing was forced on people who faced almost no risk from Covid,\u201d said another widely read post<\/a>. \u201cIt is completely unacceptable.\u201d The post shared statistics from the paper without making it clear that serious health problems after vaccination were rare and that risk varied by vaccine type and dose.<\/p>\n\n\n\n

The Vaccine study confirmed that the Moderna and Pfizer\/BioNTech vaccines are linked in rare cases to myocarditis and pericarditis, conditions involving<\/a> inflammation of the heart muscle and lining. The rate of myocarditis was most elevated after the second dose of the Moderna vaccine. Myocarditis risk \u2014 which is greatest in men in their late teens and early twenties \u2014 was identified<\/a> via vaccine safety monitoring and first reported in 2021. Based on the current evidence, the CDC<\/a> says, the benefit of vaccination outweighs the risk of these conditions, which improve for most people after medical treatment and rest.<\/p>\n\n\n\n

The study confirmed neurological and blood clotting conditions associated with the AstraZeneca vaccine. In the U.S., these problems<\/a> were linked<\/a> to the Johnson & Johnson vaccine, contributing to this vaccine no longer being recommended or available.<\/p>\n\n\n\n

The study also identified a new possible safety signal indicating a potential link between the first dose of the Moderna and AstraZeneca vaccines and rare neurological conditions. This included an association between the first doses of the vaccines and acute disseminated encephalomyelitis, or ADEM, an autoimmune condition<\/a> that causes<\/a> inflammation of the brain and spinal cord.<\/p>\n\n\n\n

Hviid emphasized that the researchers only saw these neurological events after first doses of the two vaccines. \u201cWe did not see these signals following further doses of these two Covid-19 vaccines, nor did we see them after any dose of the Pfizer\/BioNTech vaccine which has been more widely used,\u201d he said.<\/p>\n\n\n\n

\u201cWe are also talking about very rare events,\u201d Hviid continued. \u201cAs an example, the association between the first dose of Moderna and acute inflammation of the brain and spine would, if causal, correspond to 1 case per 1.75 million vaccinated. It is only due to the sheer scale of our study, that we have been able to identify this minute potential risk.\u201d<\/p>\n\n\n\n

Study Bolsters the Evidence Serious COVID-19 Vaccine Side Effects Are Rare<\/h2>\n\n\n\n

The Vaccine study<\/a> drew on national or regional health records from eight countries with institutions participating in the Global Vaccine Data Network<\/a>, an international group that studies vaccine safety. The researchers analyzed health outcomes after around 184 million doses of the Pfizer\/BioNTech vaccine, 36 million doses of the Moderna vaccine and 23 million doses of the AstraZeneca vaccine. <\/p>\n\n\n\n

The researchers focused on 13 health problems that either had a known association with vaccination or for which there was some rationale to investigate whether there was an association. To determine whether the health problems were associated with vaccination, they compared the expected rates of the health problems \u2014 or the number of health events that should occur based on background rates in the regions studied \u2014 with the number of events they observed in the 42 days after vaccination.<\/p>\n\n\n\n

\u201cThis study confirms the primary already detected and validated side effects established by previous literature,\u201d Jeffrey S. Morris<\/a>, director of the division of biostatistics at the University of Pennsylvania\u2019s Perelman School of Medicine, told us via email, referring to the rare heart conditions associated with the Moderna and Pfizer\/BioNTech vaccines, as well as the rare conditions associated with the AstraZeneca and Johnson & Johnson vaccines. <\/p>\n\n\n\n

Morris said that findings on ADEM \u2014 the rare autoimmune neurological condition linked to first doses of the Moderna and AstraZeneca vaccines \u2014 \u201cmight be a new safety signal.\u201d <\/p>\n\n\n\n

ADEM involves<\/a> inflammation to the brain and spinal cord, arising most often in children following an infectious illness. It has a sudden onset<\/a> and typically eventually improves, with a full recovery in many, although not all, cases.<\/p>\n\n\n\n

After the first dose of the Moderna vaccine, researchers observed seven ADEM cases, when they expected two. As we\u2019ve said, Hviid calculated the rate of this side effect \u2014 if ultimately shown to be related to vaccination \u2014 to be 1 in 1.75 million following the first dose of the Moderna vaccine. <\/p>\n\n\n\n

The data show \u201cthis was indeed an EXTREMELY rare adverse event,\u201d Morris said, referring to ADEM. \u201cIt is understandable at this incidence rate why it may not have been detected before now, and why a study with 99 million participants like this is important to find even the most rare serious adverse events that are potential minority harm risks of these vaccines.\u201d<\/p>\n\n\n\n

The authors of the study wrote that more research is needed into ADEM following COVID-19 vaccination, saying that \u201cthe number of cases of this rare event were small and the confidence interval wide, so results should be interpreted with caution and confirmed in future studies.\u201d The authors also wrote that neurological events<\/a> have been found to occur at a much higher rate after COVID-19 than after COVID-19 vaccination.<\/p>\n\n\n\n

The study means that \u201cearly warning systems are solid,\u201d said Marc Veldhoen<\/a>, an immunologist at the Instituto de Medicina Molecular Jo\u00e3o Lobo Antunes in Portugal, in a post<\/a> on X, formerly known as Twitter. \u201cTo avoid any adverse reaction is not possible, but, identifying those at higher risk may be possible.\u201d<\/p>\n\n\n\n

Identifying those at greater risk of side effects can help guide decisions on which vaccines to recommend and what problems doctors should watch for in their patients.<\/p>\n","protected":false},"excerpt":{"rendered":"

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