- New variants of SARS-CoV-2 are more virulent and transmissible than the original variant of the virus.
- Health experts associate these variants of concern (VOCs) with increased risk of hospitalization, intensive care unit (ICU) admission, and death.
- Vaccination reduces the risks of severe disease and death even with the VOCs.
- However, even with increased vaccination, control measures are needed to reduce the spread of the VOCs.
A Canadian study has found a link between the new variants of SARS-CoV-2, particularly the Delta variant, and an increased risk of severe disease and death.
The retrospective study, by the University of Toronto and appearing in the Canadian Medical Association Journal (CMAJ), looked at 212,326 cases in Ontario from February 7 to June 27, 2021. The study authors compared the risks of hospitalization, ICU admission, and death from the VOCs with those risks from non-VOC SARS-CoV-2 strains.
The researchers screened the cases for Alpha, Beta, Gamma, and Delta VOCs. Non-VOC infections made up 22.4% of the cases. More than three-quarters of the cases were Alpha, Beta, or Gamma, while 2.8% were probably Delta.
Alpha, Beta, and Gamma variants have a mutation that increasesTrusted Source transmission, while Delta has a mutation that increases its ability to replicate.
The authors note that before May 2021, there was no routine screening for the Delta variant, so it is likely that the numbers underestimate the prevalence of this variant.
Increased risk from the Delta variant
The present study found that all VOCs increased people’s risk of hospitalization, ICU admission, and death due to COVID-19.
However, the highest risks were from the Delta variant. In the Delta cases, there was a 108% increase in the risk of hospitalization, a 235% increased risk of ICU admission, and a 133% higher risk of death, compared with the original variant.
These effects were present even when the researchers adjusted the data for factors such as age, sex, vaccination status, and comorbidities.
Prof. William Schaffner, infectious diseases specialist at the Vanderbilt University Medical Center in Nashville, TN, commented:
“This important study from Canada reinforces the serious impact the Delta variant is having. It is well recognized that Delta is more contagious than other virus variants. This new study convincingly reinforces the finding that it also causes more severe disease.”
The Delta variant is now the dominant variant in the European Union, the United Kingdom, and the United States.
The findings of the present study corroborate those of the studies in EnglandTrusted Source, ScotlandTrusted Source, and Singapore that have also shown increased risks from the Delta variant.
Speaking to Medical News Today, Dr. Christopher Coleman, assistant professor of infection immunology at the University of Nottingham in the U.K., highlighted the international relevance of the study.
He said, “Although this [Canadian] study has some limitations, as acknowledged by the authors, this is exactly the kind of study that helps ‘build a picture’ by showing that similar observations can be observed in a lot of different circumstances.”
“It is not something unique about the U.K. that means the Delta variant is associated with more dangerous infections only here,” he added.
News
How Missing Sleep Lets Bad Memories Haunt Your Mind
Research reveals that a lack of sleep can hinder the brain’s ability to suppress unwanted memories and intrusive thoughts, emphasizing the importance of restful sleep for mental health. Sleep deprivation has been found to [...]
WHO issues new warning over ‘mystery virus’ and calls for return of COVID restrictions
The World Health Organization (WHO) has called for the reinstatement of restrictions implemented during the COVID-19 pandemic as cases of human metapneumovirus (HMPV) continue to surge. While hospitals in China are overwhelmed with positive [...]
A Breath Away From a Cure: How Xenon Gas Could Transform Alzheimer’s Treatment
A breakthrough study highlights Xenon gas as a potential game-changer in treating Alzheimer’s disease, demonstrating its ability to mitigate brain damage and improve cognitive functions in mouse models. A forthcoming clinical trial aims to test its [...]
False Memories Under Fire: Surprising Science Behind What We Really Recall
New research challenges the ease of implanting false memories, highlighting flaws in the influential “Lost in the Mall” study. By reexamining the data from a previous study, researchers found that many supposed false memories [...]
Born Different? Cambridge Scientists Uncover Innate Sex Differences in Brains
Cambridge researchers found that sex differences in brain structure exist from birth, with males having more white matter and females more grey matter, highlighting early neurodiversity. Research from the Autism Research Centre at the University [...]
New study shows risk factors for dementia – virus causes deposits in the brain
Research into the causes of Alzheimer's is not yet complete. Now a new study shows that head trauma can activate herpes viruses and promote the disease. Frankfurt am Main – As a neurodegenerative disease, [...]
Are Machines Truly Thinking? Modern AI Systems Have Finally Achieved Turing’s Vision
Modern AI systems have fulfilled Turing’s vision of machines that learn and converse like humans, but challenges remain. A new paper highlights concerns about energy consumption and societal inequality while calling for more robust [...]
The Surprising Link Between Smell, Sound, and Emotions
New research reveals how smell and hearing interact in the brain to drive social behavior, using mouse maternal instincts as a model. Imagine you’re at a dinner party, but you can’t smell the food [...]
Brain cells age at different rates
As our body ages, not only joints, bones and muscles wear out, but also our nervous system. Nerve cells die, are no longer fully replaced, and the brain shrinks. "Aging is the most important risk factor [...]
Long COVID Breakthrough: Spike Proteins Persist in Brain for Years
Researchers have discovered that the SARS-CoV-2 spike protein persists in the brain and skull bone marrow for years after infection, potentially leading to chronic inflammation and neurodegenerative diseases. Researchers from Helmholtz Munich and Ludwig-Maximilians-Universität (LMU) have [...]
Water-Resistant Paper Could Revolutionize Packaging and Replace Plastic
A groundbreaking study showcases the creation of sustainable hydrophobic paper, enhanced by cellulose nanofibres and peptides, presenting a biodegradable alternative to petroleum-based materials, with potential uses in packaging and biomedical devices. Researchers aimed to [...]
NIH Scientists Discover Game-Changing Antibodies Against Malaria
Novel antibodies have the potential to pave the way for the next generation of malaria interventions. Researchers at the National Institutes of Health (NIH) have identified a novel class of antibodies that target a previously unexplored region [...]
Surprising Discovery: What If Some Cancer Genes Are Actually Protecting You?
A surprising discovery reveals that a gene previously thought to accelerate esophageal cancer actually helps protect against it initially. This pivotal study could lead to better prediction and prevention strategies tailored to individual genetic [...]
The Cancer Test That Exposes What Conventional Scans Miss
Researchers at UCLA have unveiled startling findings using PSMA-PET imaging that reveal nearly half of patients diagnosed with high-risk prostate cancer might actually have metastases missed by traditional imaging methods. This revelation could profoundly affect future [...]
Pupil size in sleep reveals how memories are processed
Cornell University researchers have found that the pupil is key to understanding how, and when, the brain forms strong, long-lasting memories. By studying mice equipped with brain electrodes and tiny eye-tracking cameras, the researchers [...]
Stanford’s Vaccine Breakthrough Boosts Flu Protection Like Never Before
Stanford Medicine researchers have developed a new method for influenza vaccination that encourages a robust immune response to all four common flu subtypes, potentially increasing the vaccine’s efficacy. In laboratory tests using human tonsil [...]
