A higher than expected number of cases of heart inflammation have occurred in people who received the Novavax anti-COVID vaccine, researchers reported in a new study.
As of August 23, 2022, 61 cases of myocarditis, pericarditis, or both, were reported after vaccination with Novavax in the World Health Organization’s vaccine safety database, Spanish researchers found.
Using rates of heart inflammation in the population before the pandemic, the researchers calculated that the number of post-vaccination cases was higher than expected.
Reporting odds ratio values greater than one indicates a higher than expected rate. For myocarditis after vaccination with Novavax, the ratio was 5.2. For pericarditis, it was 24.75. For myopericarditis, or both conditions at the same time, it was 14.4.
Heart inflammation is a known side effect of Pfizer and Moderna’s anti-COVID vaccines, which use messenger RNA (mRNA) technology, but little data has been collected on the condition after vaccination with Novavax, which does not contain mRNA. .
The US Food and Drug Administration, when it authorized the Novavax injection during the summer of 2022, noted in its fact sheets that clinical trials indicate that there are increased risks of myocarditis and pericarditis after receiving the Novavax vaccine. In trial data submitted to the regulatory body, five cases of one or both conditions were reported in vaccinees and zero in placebo recipients. Since then, US authorities have authorized a Novavax booster, recently reaching an agreement to obtain up to 1.5 million doses, in addition to the original batch.
The European Medicines Agency did not initially warn about inflammation after vaccination with Novavax, but later added a warning to its product information.
The majority of real-world cases of myocarditis, pericarditis, or myopericarditis after Novavax vaccination (50) were reported in Australia, according to the new study. Two have been reported in the United States and nine in Europe. Most have been among people aged 18 to 44.
While the exact mechanism for the induction of myocarditis has yet to be confirmed, the study authors noted that all of the vaccines from Pfizer, Moderna, and Novavax use nanoparticles to deliver a spike protein into the body.
“Further research would be needed to understand the role of nanoparticles in the potential risk of vaccine-induced myocarditis,” they said.
The researchers, who also found a higher than expected number of reports for the Pfizer and Moderna vaccines, said health professionals should be aware that Novavax can cause myocarditis, pericarditis, or both.
The study was published in Drugs-Real World Outcomes on February 14. It was funded by CIBERSAM, a research network.
Novavax said in 2022, based on its interpretation of all its clinical trials, that there was “insufficient evidence to establish a causal relationship” between the vaccine and inflammation. In an emailed statement after being asked to comment on the new study, the company said: “Reports of myocarditis or pericarditis after vaccination with Nuvaxovid are rare. Although the risk of developing myocarditis or pericarditis is very low, both are important identified risks of anti-COVID vaccines, including Nuvaxovid.”
Nuvaxovid is the trade name of the company’s vaccine.
The company also stated that reports of inflammation “have generally been mild, self-limiting, and clinically consistent with the literature describing myocarditis after COVID-19 mRNA vaccination.” Several post-vaccination cases among those who received the Pfizer or Moderna vaccine did not resolve months later, and some ended in deaths.
Some experts have warned against receiving one of the vaccines if a person has a history of myocarditis or pericarditis, or develops it after vaccination.
“The development of myocarditis or pericarditis after a dose of an mRNA COVID-19 vaccine (i.e., Moderna or Pfizer-BioNTech) or Novavax COVID-19 vaccine is a precaution for a subsequent dose of any anti-COVID vaccine and, in general, subsequent doses should be avoided,” the US Centers for Disease Control and Prevention states on its website.
Australian authorities state that people who have experienced myocarditis or pericarditis “can receive a COVID-19 vaccine”, but advise consulting an expert “about the best time for vaccination and whether additional precautions are recommended”.
The regulator notes that some of the cases of vaccine-induced myocarditis have resulted in death.
Based on case reports, some people who suffered inflammation of the heart after a vaccination have been revaccinated.
Two cases in an Australian medical paper described a healthy 26-year-old man who experienced pericarditis after a second dose of Pfizer’s vaccine. The symptoms disappeared. Six months later, he received a booster produced by Novavax. He was diagnosed with pericarditis after experiencing similar symptoms, including chest pain.
Meanwhile, a 25-year-old woman developed chest pain and other problems 48 hours after receiving a second dose of the Pfizer vaccine. The woman, diagnosed with myopericarditis, experienced “persistent symptoms” that required returning to the hospital multiple times over five months.
The symptoms eventually disappeared and the abnormalities seemed to disappear. The woman then took a booster of the Novavax vaccine. Five days later, she experienced chest pain and similar symptoms. She was diagnosed with myocarditis. Symptoms persisted for two months after vaccination and have not been reported to have subsided.
Join our Telegram channel to receive the latest news instantly by clicking here
© The Epoch Times in Spanish. All rights reserved. Its reproduction is prohibited without express permission.
How can you help us keep reporting
Why do we need your help to fund our news coverage in the United States and around the world? Because we are an independent news organization, free from the influence of any government, corporation or political party. Since the day we started, we have faced pressure to silence ourselves, especially from the Chinese Communist Party. But we will not fold. We depend on your generous contribution to continue practicing traditional journalism. Together, we can continue to spread the truth.