Every time the coronavirus passes from person to person it picks up tiny changes to its genetic code, but scientists are starting to notice patterns in how the virus is mutating.
Now, a year after the global COVID-19 pandemic started, the issue of mutations looms at large. New variants capable of spreading faster are emerging and leading to inevitable questions about managing this pandemic and future lockdown. To date, there is little evidence, but scientists are already starting to explore how the COVID-19 virus will mutate in the future and whether they might be able to head it off.
Research from Cambridge
Over the course of 101 days, clinicians at Addenbrookes Hospital in Cambridge, UK, took 23 swab samples from one patient as he fought against the disease. Each swab was sent off to a nearby laboratory to be analysed but when virologists looked at the virus’ genetic material in the samples, they noticed something astonishing – COVID-19 was evolving before their eyes.
"We saw some remarkable changes in the virus over that time," says Dr Ravinda Gupta, an infectious diseases consultant at the hospital and a clinical microbiologist at the University of Cambridge who analysed the patient’s samples. “We saw mutations that seemed to suggest the virus was showing signs of adaptation to avoid the antibodies in the convalescent plasma treatment. It was the first time we had seen something like this happening in a person in real time.”
International Genetic Database created
Among the mutations Gupta and his colleagues identified was a deletion of two amino acids - known as H69 and V70 - in the spike protein sitting on the outside of the COVID-19 virus. This protein plays a key role in the ability of the coronavirus to infect cells.
When Gupta and his team looked closer at the spike protein deletion they had spotted, it produced concerning results. "We did some infection experiments using artificial viruses and they showed that the H69/V70 deletion mutation increases the infectivity by twofold," says Gupta. This prompted the researchers to scour the international genetic databases of COVID-19.
"We wanted to see what was happening worldwide and we stumbled upon this big expanding group of [H69/V70 deletion] sequences in the UK," says Gupta. "When we looked more closely, we found that there was a new variant causing a big outbreak.”
The new COVID-19 Variants
Alongside this genetic change, they also found 16 other mutations that had altered the viral proteins they coded for, including several on the spike protein. What they had discovered was a new lineage of the COVID-19 virus that had picked up multiple mutations over a relatively short period of time. They designated it B117 – the new British COVID-19 variant, also known as VOC 202012/01. It cut a path across the UK and had spread to 50 other countries by mid-January.
Another variant of concern found to be circulating in New York in February has also troubled scientists. This variant, designated B1.526, has been increasing in numbers and by mid-February accounted for 12.3% of the viruses analysed. It contains two key mutations – E484K and N501Y – that were also seen in the variants of concern from Brazil and South Africa.
The emergence of these new variants, which is estimated to be 50 to 75% more transmissible than the original COVID-19, along with others being detected such as the South African and Brazilian variants, has shone a spotlight on how the coronavirus is mutating as the pandemic rumbles on. It has also raised concerns about how it might continue to change in the future as we fight it with vaccines.
Updating the Vaccine Yearly
"To me these seem like a glimpse into the future where we are going to be in an arms race with this virus, just like we are with the flu," says a viral evolutionary biologist and Professor at Harvard University. “Each year the flu vaccine has to be updated as the influenza virus mutates and adapts to escape the immunity already present in the population. If the coronavirus shows similar capabilities, it could mean we will have to adopt similar tactics to keep it at bay, by regularly updating vaccines.