Researchers analyzed data on three variants of concern and found that viral loads were higher and infection lasted longer for the B.1.1.7 variant. They all were more infectious than the original strain, and transmissibility also depended on population demographics.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved since it first emerged in late 2019. Several mutations of the virus have since been observed, with some variants appearing more infectious than the original strain, which also appear to evade immunity gained by previous infections.
Some of these variants have been labeled as variants of concern (VOC) because of their greater transmissibility and infectiousness. These have also been associated with second and third waves in the infections in many countries, leading to their close monitoring, either by sequencing the complete viral genome or reverse-transcription polymerase chain reaction (RT-PCR).
Some RT-PCR studies have suggested that the VOCs may be causing higher viral loads, but those studies were done only at one-time point. In a new study published on the medRxiv* preprint server, researchers from France report how different variants affect virus kinetics in infections.
Testing virus loads
The researchers used data from RT-PCR tests specific to variants performed between February and April 2021 on SARS-CoV-2 positive samples. They used data from more than 17,000 samples. About 73% of the samples were of the B.1.1.7 variant, 6% of the B.1.351 or P.1 variants, and the rest were wild-type.
A model was developed that included several co-factors, such as the patient’s age, the virus lineage, and whether the patient was hospitalized.
They found that the viral loads were different between the wild-type virus and the different variants. For the B.1.1.7 strain, peak virus load increased with age. The cycle threshold values for the B.1.351 and P.1 strains were slightly lower than that for the wild-type strain, indicating slightly lower viral loads for these variants.
In addition, the rate of decrease of viral load with time was lower for the B.1.1.7 strain compared to the wild-type virus. The data also showed higher peak loads and a lower rate of viral load decrease in hospitalized individuals, about 1.5 days more.
News
Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artificial Intelligence
A new book by Frank Boehm, NanoappsMedical Inc. Founder. This groundbreaking volume explores the vision of a Global Health Care Equivalency (GHCE) system powered by artificial intelligence and quantum computing technologies, operating on secure [...]
New Book! NanoMedical Brain/Cloud Interface – Explorations and Implications
New book from Frank Boehm, NanoappsMedical Inc Founder: This book explores the future hypothetical possibility that the cerebral cortex of the human brain might be seamlessly, safely, and securely connected with the Cloud via [...]
Miller School Researchers Pioneer Nanovanilloid-Based Brain Cooling for Traumatic Injury
A multidisciplinary team at the University of Miami Miller School of Medicine has developed a breakthrough nanodrug platform that may prove beneficial for rapid, targeted therapeutic hypothermia after traumatic brain injury (TBI). Their work, published in ACS [...]
COVID-19 still claims more than 100,000 US lives each year
Centers for Disease Control and Prevention researchers report national estimates of 43.6 million COVID-19-associated illnesses and 101,300 deaths in the US during October 2022 to September 2023, plus 33.0 million illnesses and 100,800 deaths [...]
Nanomedicine in 2026: Experts Predict the Year Ahead
Progress in nanomedicine is almost as fast as the science is small. Over the last year, we've seen an abundance of headlines covering medical R&D at the nanoscale: polymer-coated nanoparticles targeting ovarian cancer, Albumin recruiting nanoparticles for [...]
Lipid nanoparticles could unlock access for millions of autoimmune patients
Capstan Therapeutics scientists demonstrate that lipid nanoparticles can engineer CAR T cells within the body without laboratory cell manufacturing and ex vivo expansion. The method using targeted lipid nanoparticles (tLNPs) is designed to deliver [...]
The Brain’s Strange Way of Computing Could Explain Consciousness
Consciousness may emerge not from code, but from the way living brains physically compute. Discussions about consciousness often stall between two deeply rooted viewpoints. One is computational functionalism, which holds that cognition can be [...]
First breathing ‘lung-on-chip’ developed using genetically identical cells
Researchers at the Francis Crick Institute and AlveoliX have developed the first human lung-on-chip model using stem cells taken from only one person. These chips simulate breathing motions and lung disease in an individual, [...]
Cell Membranes May Act Like Tiny Power Generators
Living cells may generate electricity through the natural motion of their membranes. These fast electrical signals could play a role in how cells communicate and sense their surroundings. Scientists have proposed a new theoretical [...]
This Viral RNA Structure Could Lead to a Universal Antiviral Drug
Researchers identify a shared RNA-protein interaction that could lead to broad-spectrum antiviral treatments for enteroviruses. A new study from the University of Maryland, Baltimore County (UMBC), published in Nature Communications, explains how enteroviruses begin reproducing [...]
New study suggests a way to rejuvenate the immune system
Stimulating the liver to produce some of the signals of the thymus can reverse age-related declines in T-cell populations and enhance response to vaccination. As people age, their immune system function declines. T cell [...]
Nerve Damage Can Disrupt Immunity Across the Entire Body
A single nerve injury can quietly reshape the immune system across the entire body. Preclinical research from McGill University suggests that nerve injuries may lead to long-lasting changes in the immune system, and these [...]
Fake Science Is Growing Faster Than Legitimate Research, New Study Warns
New research reveals organized networks linking paper mills, intermediaries, and compromised academic journals Organized scientific fraud is becoming increasingly common, ranging from fabricated research to the buying and selling of authorship and citations, according [...]
Scientists Unlock a New Way to Hear the Brain’s Hidden Language
Scientists can finally hear the brain’s quietest messages—unlocking the hidden code behind how neurons think, decide, and remember. Scientists have created a new protein that can capture the incoming chemical signals received by brain [...]
Does being infected or vaccinated first influence COVID-19 immunity?
A new study analyzing the immune response to COVID-19 in a Catalan cohort of health workers sheds light on an important question: does it matter whether a person was first infected or first vaccinated? [...]
We May Never Know if AI Is Conscious, Says Cambridge Philosopher
As claims about conscious AI grow louder, a Cambridge philosopher argues that we lack the evidence to know whether machines can truly be conscious, let alone morally significant. A philosopher at the University of [...]















