DEVELOPING Hurricane Milton strengthens into a Category 5 storm. Florida orders evacuations
Hurricane Milton strengthens into a Category 5 storm off Mexico and threatens Florida, forecasters say.
A new study has found that COVID-19 antibody treatments aren't as effective for new variants due to the evolving mutations of the differing virus strains.
Authors behind the study, which was published Tuesday in peer-reviewed journal Biochemistry, say the findings could be used to better inform the development of vaccines and therapeutics in the fight against emerging coronavirus variants.
University of Colorado Anschutz Medical Campus professor and corresponding author Krishna Mallela says the study can also aid scientists in understanding the properties of current and new variants.
"Earlier studies, including ours, have focused on explaining the effect of single mutations and not the mechanism underlying the co-evolution of mutations," Mallela said in a press release.
"Our study helps explain the concept of convergent evolution by balancing positive and negative selection pressures."
According to scientists, the study provides the "physical basis" for why currently approved antibody therapeutics are not working in neutralizing recent COVID-19 variants, such as the highly transmissible Omicron variant as well as its subvariants.
"Understanding the mechanisms underlying the antibody escape and the location of mutations in the spike protein will help in developing new antibody therapeutics that will work against new variants by targeting epitopes with minimal mutations or developing broad neutralizing antibodies that target multiple epitopes," Mallela said.
According to the study, researchers found that certain mutations appear multiple times in emerging variants showing what is known as convergent evolution.
Scientists note that one such evolution occurs at three amino acid positions -- K417, E484 and N501 -- in the COVID-19 spike protein's receptor binding domain (RBD). The study reports that nearly half of 4.3 million variant sequences in the GISAID database that contain any of these three mutations have all three occurring together.
When individual mutations are joined, the study says damaging or adverse effects are cancelled out, leading to improved selection of the mutations together.
Researchers examined the physical mechanisms underlying the convergent evolution of these three mutations. According to the study, they looked at the individual and collective effects of these mutations on antibody binding to cell receptors and immune escape, as well as protein stability and expression.
The study found the three RBD mutations perform "very distinct and specific roles" that contribute to them often being found together and improving the "viral fitness" of COVID-19 variants -- how efficiently a virus can pass through its entire life cycle.
According to the study, K417 was found to escape Class 1 antibodies, showing increased stability and expression but decreased binding ability.
E484 was found to escape Class 2 antibodies, however, scientists found it had decreased receptor binding, stability and expression.
The study said N501Y showed increased receptor binding, but also had decreased stability and expression.
When these mutations come together, scientists found that the harmful effects are mitigated due to the presence of "compensatory effects" which correct a loss of viral fitness due to earlier mutations.
The study reports that when these three mutations are found together, they show increased receptor binding, escape both Class 1 and Class 2 antibodies, and present similar stability and expression as the original strain of SARS-CoV-2. This is why treatment geared towards the original virus strain is less effective.
The study's authors say the findings suggest that the collective effect of these mutations is "far more advantageous" for virus fitness than individual mutations. They added that the presence of multiple mutations improves the selection of individual mutations.
"As SARS-CoV-2 has evolved from Alpha to Omicron, more and more mutations are accumulating. We hope that by providing research that understands the role of these mutations, we can help further propel research and the development of new therapies to better combat new variants," Mallela said in the release.
Hurricane Milton strengthens into a Category 5 storm off Mexico and threatens Florida, forecasters say.
Scurvy is not just an archaic diagnosis of 18th-century seafarers and doctors should watch for possible cases, according to researchers following a recent case.
Lawyers representing the Ontario man accused of selling hundreds of suicide kits with deadly effect around the globe have filed to intervene in a case in Canada’s highest court, arguing there is no way he can be charged with murder under Canadian law.
A British doctor on Monday admitted trying to kill his mother's long-term partner, who stood between him and an inheritance, by injecting the man with poison disguised as a COVID-19 vaccine.
Ceremonies, events and protests are being held across Canada today to mark the anniversary of a Hamas attack on Israel that triggered the ongoing war in Gaza.
During the Los Angeles Lakers' preseason game against the Phoenix Suns, LeBron and Bronny James became the first father/son duo to play together on an NBA team.
A man stole a police car and drove it onto the field of an East Vancouver park Sunday morning, placing 'dozens of bystanders in harm’s way,' according to police.
Lawyers for a man who is also under investigation in the 2007 disappearance of British toddler Madeleine McCann called on Monday for him to be acquitted in his trial on charges of unrelated sexual offences.
Christopher Ciccone, a multihyphenate artist, dancer, designer and younger brother of Madonna, has died. He was 63.
A unique form of clouds made an appearance over the skies of Ottawa on Sunday evening.
Bernie Hicks, known as the ‘Batman of Amherst,’ always wanted to sit in a Batmobile until a kind stranger made it happen.
Bubi’s Awesome Eats, located on University Ave West took to social media to announce the closure on Friday.
Weeneebayko Area Health Authority and the Government of Ontario have awarded a $1.8 billion fixed-price contract to design, build and finance a new Far North hospital.
Manitobans are in cleanup mode after intense winds barreled through southern parts of the province this weekend.
Avry Wortman, 13, scored two touchdowns on Sunday during her team's win in the under 14 Greater Moncton Football Association.
A gargantuan gourd – affectionately named ‘Orangina’ by the urban gardeners who grew it in the front yard of their Vancouver home – earned the massive honour of being named B.C.’s heaviest giant pumpkin Saturday.
Chantal Kreviazuk is set to return to Winnipeg to mark a major milestone in her illustrious musical career.
From the beaches of Cannes to the bustling streets of New York City, a new film by a trio of Manitoba directors has toured the international film festival circuit to much pomp and circumstance.