Recently the media have reported that scientists have discovered mutations in the coronavirus which are helping it adapt to humans and potentially spread faster.

The scientists in question have posted an early summary of their research, which analysed 5,300 samples of the new virus from 62 countries to look at how its genetic code has been changing over time. Overall, they found that the virus had not changed much since it first spread into humans.

There was evidence that a few of the changes they identified might be helping the virus to survive in humans, but more research is needed to understand what impact these changes have.

Viruses naturally acquire changes in their genetic code over time. Research such as this is important in keeping a track of these changes so that approaches to detecting and treating the virus can be adapted if needed.

 

Where did the story come from?

Several media outlets including the UK’s Independent recently reported on this study from researchers at the London School of Hygiene and Tropical Medicine. The researchers posted a preliminary summary of their results online to allow other researchers to read them and give feedback. The results will undergo more quality checking once they are sent to a journal for publication.

 

What is the basis for the claim?

The scientists compared the full genetic code of 5,349 samples of the new coronavirus collected in 62 countries between late December 2019 and early April 2020. They compared these to the genetic code of an early sample of the virus collected in Wuhan, to look for any changes.

They identified 3,502 single “letter” changes (mutations) across the genetic codes analysed. Using this information, they mapped how the changes arose over time in different strains as the virus spread between countries.

A few of the changes appeared to have arisen in several different strains independently. This suggested that these changes might be helping these viruses to survive. This included one change in the code for the crucial ‘spike’ protein which the virus uses to infect human cells. There were also other less common mutations in the code that could also change this spike protein. As some of the vaccines in development are targeting this spike protein, changes to it might affect how well they work.

There are limitations, as the number of samples analysed is small compared to the total number of infections and may not be representative of samples from people who are mildly affected or asymptomatic who are less likely to have been tested.

One of the researchers, Professor Martin Hibberd, has said “Overall, the virus seems very well adapted to humans and has not changed very much following its movement from animals to humans, reflected in the relatively small number of mutations observed. However, a few key mutations may have developed through selection for increased transmission.” He called for more research to see how these mutations might be benefitting the virus.

 

What do trusted sources say?

Changes to the coronavirus genetic code are important as they may change how well we are able to detect, prevent or treat it. As such, a lot of research is ongoing worldwide to collect, share and analyse genetic information on the virus.

For example, in the US the Centers for Disease Control and Prevention (CDC) has set up a consortium called SARS-CoV-2 Sequencing for Public Health Emergency Response, Epidemiology and Surveillance (SPHERES) to help coordinate efforts to collect and use data on genetic code of coronavirus in the US.

Analysis by EIU Healthcare, supported by Reckitt Benckiser

 

Citation

  1. The Independent. Coronavirus adapting to humans with mutations that could help it spread, scientists fear. Available at: https://www.independent.co.uk/news/science/coronavirus-news-latest-study-mutations-human-transmission-a9508086.html. Accessed 18 May 2020.

Reading list

  1. Phelan et al. Controlling the SARS-CoV-2 outbreak, insights from large scale whole genome sequences generated across the world. Available at: https://www.biorxiv.org/content/10.1101/2020.04.28.066977v1.full#ref-11 Accessed 18 May 2020.