New, more infectious SARS-CoV-2 variant does not cause worse symptoms


RESEARCH shows that a new variant of SARS-CoV-2, which is now the dominant form of the virus, is more infectious in cell cultures. However, clinical data suggest that the variant does not cause more severe illness.
All viruses mutate, and the new coronavirus, SARS-CoV-2, is no exception. As an RNA virus, the new coronavirus is highly prone to mutation, partly because the replication enzymes of RNA viruses make more mistakes when copying genetic material.
Although the virus is mutating slowly, scientists had raised concerns that some of the mutations could make the virus more infectious.
One mutation in particular – D614G – has been a focus of concern, as it occurs in the spike protein of the virus. This site is important because it is the spike protein that attaches to host cells and eventually leads to their infection.
The G614 variant first piqued the study team’s interest in April, when they noticed a repeated pattern across the globe.
Bette Korber, a theoretical biologist at LANL and lead author of the study, explains, “All over the world, even when local epidemics had many cases of the original form circulating, soon after the D614G variant was introduced into a region, it became the prevalent form.”
Korber’s team developed a bioinformatics tool to identify mutations in the spike protein that were becoming more common, using the SARS-CoV-2 sequence database hosted by GISAID. Tens of thousands of SARS-CoV-2 genetic sequences are available on GISAID, which has become the standard for sharing sequences among Covid-19 researchers.
COVID-19: HOW DO WE EXPLAIN ‘HAPPY’ HYPOXIA? New research suggests that the seemingly unusual phenomenon of “happy” hypoxia, or silent hypoxemia, in people with COVID-19 can be explained by long-established principles of respiratory science.
A new study has suggested that “long-established principles of respiratory physiology” can explain the otherwise confusing presence of silent hypoxemia patients with COVID-19.
The ongoing Covid-19 pandemic holds many mysteries. Among the more baffling has been the frequency of silent hypoxemia, or happy hypoxia, as it has been dubbed in the media.
Hypoxemia is defined as “a decrease in the partial pressure of oxygen in the blood.” As blood oxygen levels begin to reduce, a person may experience shortness of breath, also called dyspnea. If blood oxygen levels continue to fall, the organs may shut down, and the issue becomes life threatening.