No serious health effects linked to mRNA COVID-19 vaccines

Press release:

Federal and Kaiser Permanente researchers combing the health records of 6.2 million patients found no serious health effects that could be linked to the 2 mRNA COVID-19 vaccines.

The study published September 2 in JAMA reports the first comprehensive findings of the Vaccine Safety Datalink (VSD), which studies patient records for 12 million people in 5 Kaiser Permanente service regions along with HealthPartners in Minneapolis, the Marshfield Clinic in Wisconsin, and Denver Health. The work is supported by the Centers for Disease Control and Prevention (CDC).

“These results from our safety surveillance are reassuring,” said lead author Nicola Klein, MD, PhD, director of the Kaiser Permanente Vaccine Study Center and principal investigator of the Vaccine Safety Datalink’s COVID-19 rapid cycle analysis.

“The world is relying on safe and effective vaccines to bring an end to the COVID-19 pandemic. The Vaccine Safety Datalink is ideally suited to carry out this important surveillance and we will continue to monitor the safety of all vaccines that protect against COVID-19,” added Dr. Klein, who is also a senior research scientist with the Kaiser Permanente Division of Research.

The study reported findings from mid-December 2020 through June 26, 2021. Some of the early findings had been summarized previously and reported at public meetings of the CDC’s Advisory Committee on Immunization Practices, though the JAMA article is the VSD’s first comprehensive report of its safety surveillance of the Pfizer and Moderna mRNA vaccines.

The analyses compared specific health events among all COVID-19 mRNA-vaccinated people during the first 3 weeks after inoculation with health events among similar types of patients during the 3 to 6 weeks after mRNA vaccination. The total number of people evaluated was 6.2 million for the first dose of either mRNA vaccine and 5.7 million for the second dose.

The design is meant to compare patients who are as similar to one another as possible to reduce the number of factors that could complicate the results. The authors added a comparison group of unvaccinated patients in a supplemental analysis.

The researchers examined 23 potential health effects, chosen because they had been included in previous vaccine studies, were of particular concern as an effect of COVID-19, were noted during the COVID-19 clinical trials, or were added after public health officials reported increased cases among vaccinated people. Outcomes tracked included neurological disorders such as encephalitis and myelitis, seizures, and Guillain-Barré syndrome; cardiovascular problems such as acute myocardial infarction, stroke, and pulmonary embolism; and others such as Bell’s palsy, appendicitis, anaphylaxis, and multisystem inflammatory syndrome.

Patient medical records were searched electronically and analysts carried out chart reviews of specific health outcomes to verify the medical problem and to assess whether it started before or after vaccination.

Vaccine Safety Datalink researchers then applied statistical analysis to determine whether the number of incidents was above a certain threshold, or “signal.” They concluded that none of the target health outcomes reached the signal, though for some outcomes the findings were less precise because of small numbers of cases. The authors said VSD safety surveillance is ongoing, which will increase the precision of estimates for those outcomes.

The study authors highlighted their findings about cases of confirmed myocarditis and pericarditis among young individuals, as that has become an outcome of concern. The VSD study identified 34 such cases in patients 12 to 39 years old; 85% of them were male and 82% hospitalized (for a median of 1 day), and nearly all recovered by the time the chart review took place. The authors calculated that among patients 12 to 39 years old, there is a risk of 6.3 additional myocarditis cases per million doses during the first week after vaccination. Other research has calculated a significantly higher risk of myocarditis from COVID-19 than from the vaccine.

“The results of this study are a great example of how seriously CDC takes vaccine safety, and how thorough and transparent we are in our safety monitoring efforts,” said Tom Shimabukuro, MD, leading vaccine safety for the COVID-19 response and the deputy director of CDC’s Immunization Safety Office. “It is our top priority to do the science and communicate quickly and clearly with healthcare providers and the public, as COVID-19 vaccines continue to undergo the most intensive safety monitoring in U.S. history. Getting vaccinated remains the best way to protect yourself and your loved ones against a virus that has taken millions of lives.”

The VSD’s rapid-cycle analysis for the mRNA COVID-19 vaccines will continue tracking newly vaccinated patients for at least 2 years. The VSD, established in 1990 and led by the CDC, Kaiser Permanente, and other health care systems, is the nation’s premier active surveillance system for vaccine safety.

One shot of the Sputnik V vaccine triggers strong antibody responses

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A single dose of the Sputnik V vaccine may elicit significant antibody responses against SARS-CoV-2, finds a study published July 13 in the journal Cell Reports Medicine.

“Due to limited vaccine supply and uneven vaccine distribution in many regions of the world, health authorities urgently need data on the immune response to vaccines to optimize vaccination strategies,” says senior author Andrea Gamarnik (@GamarnikLab) of the Fundación Instituto Leloir-CONICET in Buenos Aires, Argentina. “The peer-reviewed data we present provide information for guiding public health decisions in light of the current global health emergency.”

Past research has shown that two doses of Sputnik V results in 92% efficacy against coronavirus disease 2019 (COVID-19), which is caused by SARS-CoV-2. An important question is whether a single dose would achieve greater public health benefit than two doses by allowing protection of a larger population more quickly.

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Blood clots related to AstraZeneca/Oxford vaccine can be mitigated with early detection

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New research has shown that early testing for blood clots in patients who had received the AstraZeneca/Oxford vaccine led to them being treated successfully, highlighting the need for heightened awareness of the risk among doctors.

The work, led by researchers from RCSI University of Medicine and Health Sciences and the National Coagulation Centre at St James’s Hospital, is published in the British Journal of Haematology.

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Long COVID symptoms likely caused by Epstein-Barr virus reactivation

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Epstein-Barr virus (EBV) reactivation resulting from the inflammatory response to coronavirus infection may be the cause of previously unexplained long COVID symptoms — such as fatigue, brain fog, and rashes — that occur in approximately 30% of patients after recovery from initial COVID-19 infection. The first evidence linking EBV reactivation to long COVID, as well as an analysis of long COVID prevalence, is outlined in a new long COVID study published in the journal Pathogens.

“We ran EBV antibody tests on recovered COVID-19 patients, comparing EBV reactivation rates of those with long COVID symptoms to those without long COVID symptoms,” said lead study author Jeffrey E. Gold of World Organization. “The majority of those with long COVID symptoms were positive for EBV reactivation, yet only 10% of controls indicated reactivation.”

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COVID-19 reinfection rate less than 1% for those with severe illness

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A review of more than 9,000 U.S. patients with severe COVID-19 infection showed less than 1% contracted the illness again, with an average reinfection time of 3.5 months after an initial positive test. Those are the findings from a study conducted by researchers from the University of Missouri School of Medicine and MU Health Care.

The researchers teamed up with the MU Institute for Data Science and Informatics and the Tiger Institute for Health Innovation to review data from 62 U.S. health care facilities. They found 63 of the 9,119 patients (0.7%) with severe COVID-19 infection contracted the virus a second time, with a mean reinfection period of 116 days. Of the 63 who were reinfected, two (3.2%) died. Patients categorized as non-white were at greater risk of reinfection than white patients.

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Vitamin D may not protect against COVID-19, as previously suggested

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While previous research early in the pandemic suggested that vitamin D cuts the risk of contracting COVID-19, a new study from McGill University finds there is no genetic evidence that the vitamin works as a protective measure against the coronavirus.

“Vitamin D supplementation as a public health measure to improve outcomes is not supported by this study. Most importantly, our results suggest that investment in other therapeutic or preventative avenues should be prioritized for COVID-19 randomized clinical trials,” say the authors.

To assess the relationship between vitamin D levels and COVID-19 susceptibility and severity, the researchers conducted a Mendelian randomization study using genetic variants strongly associated with increased vitamin D levels. They looked at genetic variants of 14,134 individuals with COVID-19 and over 1.2 million individuals without the disease from 11 countries.

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Researchers uncover mechanism related to severe post-COVID-19 disease in children

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A multidisciplinary team from MassGeneral Hospital for Children (MGHfC), Brigham and Women’s Hospital and other institutions have identified the mechanism of how an extremely rare but serious post-COVID-19 complication develops in children and adolescents. Led by MGHfC pediatric pulmonologist Lael Yonker, MD, researchers determined that viral particles remaining in the gut long after an initial COVID-19 infection can travel into the bloodstream, instigating the condition called Multisystem Inflammatory Syndrome in Children (MIS-C).

The syndrome can occur several weeks after an initial infection; symptoms include high fever, abdominal pain, vomiting, diarrhea, rash and extreme fatigue. The hyperinflammatory response and “cytokine storm” seen in MIS-C can lead to extensive damage in the heart, liver and other organs.

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Direct-acting antiviral to treat COVID-19

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An international team of scientists from the Menzies Health Institute Queensland (MHIQ) at Griffith University and from City of Hope, a research and treatment center for cancer, diabetes and other life-threatening diseases in the U.S., have developed an experimental direct-acting antiviral therapy to treat COVID-19.

Traditional antivirals reduce symptoms and help people recover earlier. Examples include Tamiflu®, zanamivir and remdesivir.

This next-generation antiviral approach used gene-silencing RNA technology called siRNA (small-interfering RNA) to attack the virus’ genome directly, which stops the virus from replicating, as well as lipid nanoparticles designed at Griffith University and City of Hope to deliver the siRNA to the lungs, the critical site of infection.

“Treatment with virus-specific siRNA reduces viral load by 99.9%. These stealth nanoparticles can be delivered to a wide range of lung cells and silence viral genes,” said co-lead researcher Nigel McMillan, Ph.D., professor and director of the Infectious Diseases & Immunology Program at MHIQ.

“Treatment with the therapy in SARS-Cov-2 infected mice improved survival and loss of disease. Remarkably, in treated survivors, no virus could be detected in the lungs,” McMillan said.

Kevin Morris, Ph.D., professor and associate director of the Center for Gene Therapy at City of Hope and co-lead researcher from both City of Hope and Griffith University said, “This treatment is designed to work on all betacoronaviruses such as the original SARS virus (SARS-CoV-1) as well as SARS-CoV-2 and any new variants that may arise in the future because it targets ultra-conserved regions in the virus’ genome.”

McMillan added, “We have also shown that these nanoparticles are stable at 4°C for 12 months and at room temperature for greater than one month, meaning this agent could be used in low-resource settings to treat infected patients.”

The results suggest that siRNA-nanoparticle formulations can be developed as a therapy to treat COVID-19 patients, as well as used for future coronavirus infections by targeting the virus’ genome directly.

“These nanoparticles are scalable and relatively cost-effective to produce in bulk,” Professor Morris said.

“This work was funded as an urgent call by Medical Research Futures Fund and is the type of RNA medicine that can be manufactured locally in Australia,” McMillan said.

COVID-19 vaccination: Thrombosis can be prevented by prompt treatment

Press Release:

A rare syndrome has been observed in people following vaccination against Covid-19. This involves thrombosis at unusual sites in the body, associated with a low thrombocyte (blood platelet) count and a clotting disorder. In medical jargon, this syndrome is referred to as VITT (vaccine-induced thrombotic thrombocytopenia). Doctors at the Department of Medicine I of MedUni Vienna and Vienna General Hospital (Division of Hematology and Hemastaseology) have now successfully treated an acute instance of this syndrome.

VITT is most probably caused by a defective immune response, whereby thrombocyte-activating antibodies are produced resulting in thrombocytopenia (low platelet count) and thrombosis. The mortality rate in VITT is high (40-50 %) and the syndrome requires immediate and appropriate treatment. However, the current recommendations are only empirical and are based on in-vitro data.

A team of doctors at the Department of Medicine I of MedUni Vienna and Vienna General Hospital, led by coagulation specialist Paul Knöbl, has now successfully treated a patient suffering from vaccine-induced prothrombotic immune thrombocytopenia (VIPIT). The female patient was admitted to the Department with a low platelet count and low fibrinogen levels. Fibrinogen is a protein that plays a major role in blood clotting. Knöbl reports: “Apart from that, her D-dimer values, which indicate thrombosis, were very high and an ELISA assay produced a clear positive result for heparin-PF4 antibodies – all signs of incipient thrombosis.”

The doctors acted quickly, and the patient responded immediately to treatment with a high dose of intravenous immunoglobulin concentrates, cortisone and specific anticoagulants, so that thrombosis was prevented. Immunoglobulin concentrates contain antibodies that can block the misdirected immune response. The usual heparin preparations must not be used to prevent clotting, since they can trigger thrombosis, or aggravate it.

“In this case we were able to describe, for the first time, the efficacy of a potentially life-saving treatment strategy for vaccine-induced thrombosis,” says Knöbl. These new findings have been published in the Journal of Thrombosis and Haemostasis. On the one hand, the findings support the current treatment recommendations, but they also show that prompt diagnosis and immediate initiation of treatment are necessary in order to prevent a life-threatening thrombosis. “This experience could be of great help in treating other patients with similar conditions.”

Why is COVID-19 so hard to treat? Growing evidence points to unique infectious profile

Press release:

A comprehensive review into what we know about COVID-19 and the way it functions suggests the virus has a unique infectious profile, which explains why it can be so hard to treat and why some people experience so-called “long-COVID”, struggling with significant health issues months after infection.

There is growing evidence that the virus infects both the upper and lower respiratory tracts – unlike “low pathogenic” human coronavirus sub-species, which typically settle in the upper respiratory tract and cause cold-like symptoms, or “high pathogenic” viruses such as those that cause SARS and ARDS, which typically settle in the lower respiratory tract.

Additionally, more frequent multi-organ impacts, and blood clots, and an unusual immune-inflammatory response not commonly associated with other, similar viruses, mean that COVID-19 has evolved a uniquely challenging set of characteristics.

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