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Infectious Diseases

Updated 03 April 2020

8 strains of coronavirus circulating around the world

Scientists are looking into the coronavius strains going around and how the virus has mutated. Here is what the latest research has uncovered.

While racing to fully understand the structure of the new coronavirus, scientists around the world have discovered that there are eight specific strains affecting the globe.

These strains are all extremely similar and the virus shows only slow mutation – which buys time for those under pressure to develop a vaccine or effective treatment.

According to reports, scientists have been using advanced technology to rapidly sequence the genome of the virus from test samples. This shows that the difference between the eight strains worldwide are minute and that none of them is necessarily weaker or worse than the other.

Scientists used their knowledge to compile a genetic sequence map at nextstrain.org, an open access website which shows how the virus travelled across the globe and how various strains developed. According to Charles Chui, infectious disease physician and clinical microbiologist, scientists have the ability to do genomic sequencing almost in real-time to see what strains or lineages are currently circulating.

How did the virus spread across the world?

The study showed that the virus spread from Wuhan, China to the UK via passengers travelling to South Korea and Singapore. From London’s largest airports, the virus then spread to the rest of Europe and the USA.

According to the scientists, there is “strong mixing of samples across Europe”, which suggests that the virus continued to move across borders in the last three to five weeks.

In the US, however, the viral samples from opposite sides of the country are almost identical. For instance, in the state of Washington, the virus has been introduced two times, and perhaps more. The origin is thought to either be China or Europe. The effect is visible as two separate chains of viral spread.

While the research gives more insight to the virus, sample numbers in some countries were too low to determine the exact spread, even though strains were similar.

Why is this so important to know?

Knowing how the virus can mutate has an important impact on how an effective vaccine is created. While the disease is asymptomatic or mild in up to 80% of people, it can cause serious respiratory failure and death in some cases. If the virus has the potential to mutate to a deadlier strain, scientists must be aware of this.

In the case of seasonal flu, for example, there is a vaccine, which is updated yearly because of rapid mutations.

In the case of the Covid-19 virus, scientists are becoming more familiar with current strains circulating and the way they mutate, which is crucial for developing an effective vaccine. Because the virus is mutating slowly, a once-off vaccine is a possibility. The other good news is that the slow mutation of the virus indicates that it's not likely to mutate to a more lethal strain.

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