In a recent study conducted at the Baylor College of Medicine, Houston, USA, scientists have identified six vaccine breakthrough cases caused by the delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
A vaccine breakthrough case is defined as the detection of SARS-CoV-2 infection in individuals who are fully vaccinated against coronavirus disease 2019 (COVID-19). The study is currently available on the medRxiv* preprint server.
Background
Recently, India has seen a significant rise in new COVID-19 cases predominantly caused by the delta variant (B.1.617.2) of SARS-CoV-2. Similar to the alpha (B.1.1.7), beta (B.1.351), and gamma (P.1) variants, the delta variant has gained beneficial mutations in the spike protein, which make it more infectious and pathogenic than previously circulating variants.
The delta variant belongs to the B.1.617 lineage that is currently circulating in more than 50 countries. Because of its significant threat to public health, the delta variant has been designated as the Variant of Concern (VOC) by the World Health Organization.
Studies investigating vaccine efficacy against emerging SARS-CoV-2 variants have indicated that the delta variant is partially resistant to vaccine-induced antibodies. A study conducted in the UK has indicated that the Pfizer/BioNTech COVID-19 vaccines is 88% effective in preventing symptomatic disease caused by the delta variant.
In the current study, the scientists have described the transmission of delta variants among family members who were attending a wedding ceremony with 92 guests. The wedding events were held outside in a large open-air tent, and all guests were fully vaccinated.
Important observations
The scientists identified a total of six individuals at the wedding ceremony who tested positive for SARS-CoV-2 and were symptomatic. Of them, one developed severe COVID-19 requiring monoclonal antibody infusion and one died eventually. Based on encounter timings and viral sequence similarities, the scientists suggested that two persons traveling from India probably have transmitted the delta variant to other guests during the wedding events.
Soon after developing symptoms including fatigue, cough, and fever, both guests from India tested positive for SARS-CoV-2 infection. At day 6 post-wedding, the man without comorbidity was admitted to a hospital because of worsening symptoms. One month after the wedding, he died due to COVID-19 related complications.
Four other guests who also tested positive for SARS-CoV-2 had confirmed interactions with the guests from India. Of 4 guests who were fully immunized with the Pfizer/BioNTech or Moderna COVID-19 vaccine, one developed severe COVID-19 that required infusion of monoclonal antibodies.
Testing of viral variant
Nasopharyngeal swab samples were collected from all six guests and analyzed by reverse transcription-polymerase chain reaction (RT-PCR) to detect viral variants. All samples tested positive for the original Wuhan strain of SARS-CoV-2 and negative for the alpha variant. All positive samples were subsequently sequenced by Swift Normalase Amplicon Panels with multiple overlapping amplicons to identify the causative variant. The findings revealed that all six guests were infected with the delta variant of SARS-CoV-2 (B.1.617.2).
News
New technique overcomes technological barrier in 3D brain imaging
Scientists at the Swiss Light Source SLS have succeeded in mapping a piece of brain tissue in 3D at unprecedented resolution using X-rays, non-destructively. The breakthrough overcomes a long-standing technological barrier that had limited [...]
Scientists Uncover Hidden Blood Pattern in Long COVID
Researchers found persistent microclot and NET structures in Long COVID blood that may explain long-lasting symptoms. Researchers examining Long COVID have identified a structural connection between circulating microclots and neutrophil extracellular traps (NETs). The [...]
This Cellular Trick Helps Cancer Spread, but Could Also Stop It
Groups of normal cbiells can sense far into their surroundings, helping explain cancer cell migration. Understanding this ability could lead to new ways to limit tumor spread. The tale of the princess and the [...]
New mRNA therapy targets drug-resistant pneumonia
Bacteria that multiply on surfaces are a major headache in health care when they gain a foothold on, for example, implants or in catheters. Researchers at Chalmers University of Technology in Sweden have found [...]
Current Heart Health Guidelines Are Failing To Catch a Deadly Genetic Killer
New research reveals that standard screening misses most people with a common inherited cholesterol disorder. A Mayo Clinic study reports that current genetic screening guidelines overlook most people who have familial hypercholesterolemia, an inherited disorder that [...]
Scientists Identify the Evolutionary “Purpose” of Consciousness
Summary: Researchers at Ruhr University Bochum explore why consciousness evolved and why different species developed it in distinct ways. By comparing humans with birds, they show that complex awareness may arise through different neural architectures yet [...]
Novel mRNA therapy curbs antibiotic-resistant infections in preclinical lung models
Researchers at the Icahn School of Medicine at Mount Sinai and collaborators have reported early success with a novel mRNA-based therapy designed to combat antibiotic-resistant bacteria. The findings, published in Nature Biotechnology, show that in [...]
New skin-permeable polymer delivers insulin without needles
A breakthrough zwitterionic polymer slips through the skin’s toughest barriers, carrying insulin deep into tissue and normalizing blood sugar, offering patients a painless alternative to daily injections. A recent study published in the journal Nature examines [...]
Multifunctional Nanogels: A Breakthrough in Antibacterial Strategies
Antibiotic resistance is a growing concern - from human health to crop survival. A new study successfully uses nanogels to target and almost entirely inhibit the bacteria P. Aeruginosa. Recently published in Angewandte Chemie, the study [...]
Nanoflowers rejuvenate old and damaged human cells by replacing their mitochondria
Biomedical researchers at Texas A&M University may have discovered a way to stop or even reverse the decline of cellular energy production—a finding that could have revolutionary effects across medicine. Dr. Akhilesh K. Gaharwar [...]
The Stunning New Push to Protect the Invisible 99% of Life
Scientists worldwide have joined forces to build the first-ever roadmap for conserving Earth’s vast invisible majority—microbes. Their new IUCN Specialist Group reframes conservation by elevating microbial life to the same urgency as plants and [...]
Scientists Find a Way to Help the Brain Clear Alzheimer’s Plaques Naturally
Scientists have discovered that the brain may have a built-in way to fight Alzheimer’s. By activating a protein called Sox9, researchers were able to switch on star-shaped brain cells known as astrocytes and turn them into [...]
Vision can be rebooted in adults with amblyopia, study suggests
Temporarily anesthetizing the retina briefly reverts the activity of the visual system to that observed in early development and enables growth of responses to the amblyopic eye, new research shows. In the common vision [...]
Ultrasound-activated Nanoparticles Kill Liver Cancer and Activate Immune System
A new ultrasound-guided nanotherapy wipes out liver tumors while training the immune system to keep them from coming back. The study, published in Nano Today, introduces a biodegradable nanoparticle system that combines sonodynamic therapy and cell [...]
Magnetic nanoparticles that successfully navigate complex blood vessels may be ready for clinical trials
Every year, 12 million people worldwide suffer a stroke; many die or are permanently impaired. Currently, drugs are administered to dissolve the thrombus that blocks the blood vessel. These drugs spread throughout the entire [...]
Reviving Exhausted T Cells Sparks Powerful Cancer Tumor Elimination
Scientists have discovered how tumors secretly drain the energy from T cells—the immune system’s main cancer fighters—and how blocking that process can bring them back to life. The team found that cancer cells use [...]
