Tuesday, September 29, 2020 | ePaper

Did a mutation help the coronavirus spread?

  • Print




The New York Times :For months, scientists have debated whether a variant of the coronavirus that has come to predominate in much of the world did so partly because it is more transmissible than other viruses.
On Thursday, a team of researchers reported new evidence that is likely to deepen the debate rather than settle it, experts said; too many uncertainties remain, in a pandemic that changes shape by the day.
The new report, posted by the journal Cell and led by investigators at Los Alamos National Laboratory, suggested that the variant did have such an advantage. Other researchers said the findings were not yet definitive.
The underlying question is as important as ever, both for understanding the early phases of the pandemic and anticipating how it will progress in the coming months. If the genetic glitch that defines the variant, known as D614G, imparted even a slight increase in transmissibility, it would help explain why infections exploded in some regions and not in others with similar density and other attributes. Others experts argue that it is far more likely that the variation spread widely by chance, multiplying outward from explosive outbreaks in Europe.
Last month, virologists at Scripps Research, Florida, found that viruses with the D614G mutation were far more infectious than those without it, at least in cell culture. Those differences are necessary for higher transmission to occur in the real world but hardly sufficient; there is no evidence that the D614G variant makes people sicker.
The new paper, led by Bette Korber, a theoretical biologist, presents evidence in the form of lab findings, tests of infected patients and a broad statistical analysis of the pandemic as the D614G variant repeatedly took over in cities, regions and countries. “The consistency of this pattern was highly statistically significant, suggesting that the G614 variant may have a fitness advantage,” the authors concluded.
In an interview, Korber said that the three lines of evidence “all support the idea this is quite likely to be a more transmissible virus” than other variants. She added, “It is the dominant virus in the world, it only took about a month for that to happen, and it’s now the one we should be looking at.”
The report also acknowledged that other alternate explanations were possible, including so-called founder effects — an advantage rooted in chance and in the dynamics of transmission in regions where the variant first took off. Other research has found no evidence of increased transmissibility for D614G, and for many scientists the question remains an open one.
“It’s exciting to see a group take on the challenge of solving this, and the differences they report are intriguing, particularly the consistency across geography,” said Dr. Marc Suchard, a biostatistician at the UCLA School of Medicine. “But this is an extraordinarily challenging problem; the evolution and demography are complex, so there’s much more work to be done.”
Korber helped focus scientists’ attention on the D614G mutation in early May when she posted a paper arguing that “when introduced to new regions it rapidly becomes the dominant form.” The new report expands on the previous one, and Korber said that her group intended to continue its investigation by testing different variants in animals to see if differences in transmission are detectable.

More News For this Category

Three accused on five-day remand: No lawyer willing to defend them

Three accused on five-day remand: No lawyer willing to defend them

Sylhet Bureau :A Sylhet court has placed another accused, Robiul Islam, on remand in a case filed for gang-raping a woman on the hostel premises of Murari Chand (MC)

Anomaly in waste collection! Contractors draw Tk 300cr from citizens, DSCC gets only Tk 9cr

Al Amin :The household waste collectors appointed by the Dhaka South City Corporation (DSCC) collect over Tk 300 crore annually from the area but the city corporation gets only Tk

Shahed gets life term in arms case

Shahed gets life term in arms case

Court Reporter :A Dhaka court on Monday sentenced Regent Group chairman Shahed Karim alias Mohammad Shahed to life term imprisonment in an arms case.Dhaka Metropolitan Sessions Judge Imrul Kayesh pronounced

Trial of China vaccine in Bangladesh to be delayed

Staff Reporter :The human trials in Bangladesh of a Covid-19 vaccine developed by Chinese company Sinovac Biotech Ltd would be delayed. It is not possible to start trial for now,

889 women raped this year: ASK

Staff Reporter :Human rights advocacy organisation Ain O Salish Kendra on Monday alleged that about 889 women were raped during January to August this year. Officials of the organisation said

39 killed as Armenia-Azerbaijan fighting enters second day

AFP :Armenian separatists in the breakaway region of Nagorny Karabakh said on Monday 15 more of its fighters have been killed in a flare-up of a territorial dispute, bringing the

Migrant workers block road in Karwan Bazar again

Staff Reporter :Hundreds of Bangladeshi Saudi migrant workers on Monday again blocked the road in front of the Saudi Arabian Airlines office at Pan Pacific Sonargaon in city for the

Shopkeeper stabbed to death in Mohammadpur

Staff Reporter :A grocer has been stabbed to death at Poolpar area of Mohammadpur in Dhaka.The deceased has been identified as Nazrul Islam, 45.The incident took place around 12pm on

Country reports 32 more Covid-19 deaths

Staff Reporter :Bangladesh's Covid-19 death toll climbed to 5,193 with 32 more fatalities.On the other hand, positive cases stood at 3,60,555 as 1,407 more virus patients were detected from 11,922

Tens of thousands march in Belarus despite police detentions

AFP, Minsk  :Belarusian police on Sunday detained around 200 people as tens of thousands took to the streets in support of protest figure Svetlana Tikhanovskaya days after the country's strongman