The immune response needed to protect people against reinfection with the coronavirus will be explored in a new human challenge trial, researchers have revealed.
Human challenge trials involve deliberately exposing healthy people to a disease-causing organism in a carefully controlled manner, and have proved valuable in understanding and tackling myriad conditions from malaria to tuberculosis and gonorrhoea.
The first human challenge trials for Covid began this year, with the study – a partnership led by researchers at Imperial College London among others – initially looking at the smallest amount of virus needed to cause infection among people who have not had Covid before.
“The point of this study is to determine what kind of immune response prevents reinfection,” said Helen McShane, a professor of vaccinology at the University of Oxford, and chief investigator on the study.
McShane said the team would measure the levels of various components of participants’ immune response – including T-cells and antibodies – and then track whether participants became reinfected when exposed to the virus.
Participants must be healthy, at low risk from Covid, aged between 18 and 30, and must have been infected with the coronavirus at least three months before joining the trial. As well as having previously had a positive Covid PCR test, they must also have antibodies to Covid. Given the timing criteria, McShane said it was likely most participants would have previously been infected with the original strain of the virus.
The first phase of the trial will initially involve 24 participants split into dose groups of three to eight people who will receive, via the nose, the original strain of coronavirus. The idea is to start with a very low dose and, if necessary, increase the dose – up to a point – between groups.
“Our target is to have 50% of our subjects infected but with no, or only very mild, disease,” said McShane, adding that once the dose required to achieve this is determined it will be administered to 10-40 other participants to confirm the dose.
Image Credit: Joseph Prezioso/AFP/Getty Images
Post by Amanda Scott, NA CEO. Follow her on twitter @tantriclens
Thanks to Heinz V. Hoenen. Follow him on twitter: @HeinzVHoenen
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 [...]
