A global study has found clear evidence that a new form of coronavirus has spread from Europe to the United States. The new mutation makes the virus more infectious but does not seem to make people sicker, an international team of researchers reported on Thursday.
The mutation affects the advanced protein – the structure that the virus uses to enter the cells it infects. Now the researchers are checking to see if it affects whether the virus can be controlled with a vaccine. The vaccines currently tested mainly target the advanced protein.
The study, published in the journal Cell, confirms previous work suggesting that the mutation had made the new variant of the virus more common. Researchers call the new mutation G614, and they show that it has almost completely replaced the first version to spread in Europe and the United States, the one called D614.
What it means: This could be good news, said Lawrence Young, a professor of medical oncology at the British University of Warwick, who was not involved in the study. “Current work suggests that while the G614 variant may be more infectious, it is not more pathogenic. There is hope that as the SARS-CoV-2 infection spreads, the virus will become less pathogenic, “he said in a statement.
About the study: The team tested samples from patients in Europe and the United States and sequenced the genomes. They compared these genome sequences to what has been shared publicly. The comparison of these sequences helped them to map the spread of the two forms.
“Until March 1, 2020, the G614 variant was rare outside Europe, but by the end of March, its frequency had increased worldwide,” they wrote.
Even when the D614 form had caused widespread epidemics, in places like Wales and Nottingham in England, as well as in Washington State, the G614 took over once it appeared, did they found.
“The increase in the frequency of G614 often continues well after the home stay controls are in place and after the next two-week incubation period,” they added.
The new version seems to multiply faster in the upper respiratory tract – the nose, sinuses and throat – which would explain why it passes more easily, according to the researchers. But tests on 1000 patients hospitalized for a coronavirus showed that those infected with the new version did not fare worse than those who had caught the original strain.
Other mutations often accompany the G614 mutation, but it is not known exactly what effect they have. “The first sequence we detected that carried the 4 mutations was sampled in Italy on February 20,” they wrote. “Within a few days, this haplotype was sampled in many European countries.
The G614 mutation can be neutralized by convalescent serum – the blood product taken from people who have recovered from a coronavirus infection, the researchers said.
“But it will be important to determine whether the D614 and G614 forms of SARS-CoV-2 are differentially sensitive to neutralization by antibodies caused by the vaccine or by antibodies produced in response to infection by one or the other. form of the virus, “they added.
More work is needed, of course, to consolidate the results and see what the changes mean for the epidemic and for patients, the researchers said.
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