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Infectious Diseases

Updated 14 July 2020

A new, more infectious - but not deadlier - coronavirus strain is now the dominant global strain

As viruses evolve, new strains develop. In the case of SARS-CoV-2, a new variation has evolved with an increased ability to infect humans.

  • A new variation of Covid-19 is even more infectious than previous strains
  • This strain is now dominating Covid-19 infections globally
  • Luckily, this viral strain is not more deadly or severe than previous strains

In just over seven months, there have been more than 11 million cases of the novel coronavirus that causes Covid-19 globally.

As the pandemic progresses, scientists are investigating how new strains develop, as this will tell us more about how the virus is spreading, and how it could affect vaccine development.

Now, new research from Sheffield University, published in the journal Cell on 6 July 2020, has shown that a new mutation of the viral genome of Covid-19 has improved its ability to infect human cells, according to a news release.

This means that the virus spreads more easily without necessarily being deadlier.  

What is this new strain?

The researchers analysed genome samples from SARS-CoV-2 and found that a variant named D614G quickly took over as the dominant strain soon after its first appearance. According to the study authors, geographic samples showed a significant shift in viral population from the original strain of the virus to this new strain.

There is a small, yet significant difference in the way the “spike” glycoprotein on the surface of the virus enters and infects human cells – making the viral load higher and more likely that someone would test positive for Covid-19.

"Data provided by our team in Sheffield suggested that the new strain was associated with higher viral loads in the upper respiratory tract of patients with Covid-19, meaning that the virus's ability to infect people could be increased,” stated Dr Thushan de Silva, Senior Clinical Lecturer in Infectious Diseases at the University of Sheffield.

His team has been sequencing SARS-CoV-2 viral genomes since early in the outbreak.

Not more severe

Even though the D614G strain proves to be extremely effective in infecting human cell cultures in lab conditions, it’s not more severe than previous Covid-19 strains, remarked Dr de Silva.

The researchers want to explore this strain further in live cells to see what the full impact of this mutation will be.

READ | 8 strains of coronavirus circulating around the world

READ | US experts optimistic in search for Covid-19 vaccine

READ | Can Covid-19 spread when you cough through a mask?

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