The 33-page report was posted Thursday on BioRxiv, a website that researchers use to share their work before it is peer reviewed, an effort to speed up collaborations with scientists working on COVID-19 vaccines or treatments. That research has been largely based on the genetic sequence of earlier strains and might not be effective against the new one.

The mutation identified in the new report affects the now infamous spikes on the exterior of the coronavirus, which allow it to enter human respiratory cells. The report’s authors said they felt an “urgent need for an early warning” so that vaccines and drugs under development around the world will be effective against the mutated strain.
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The Los Alamos team, assisted by scientists at Duke University and the University of Sheffield in England, identified 14 mutations. Those mutations occurred among the nearly 30,000 base pairs of RNA that other scientists say make up the coronavirus’s genome. The report authors focused on a mutation called D614G, which is responsible for the change in the virus’ spikes.

“The story is worrying, as we see a mutated form of the virus very rapidly emerging, and over the month of March becoming the dominant pandemic form,” study leader Bette Korber, a computational biologist at Los Alamos, wrote on her Facebook page. “When viruses with this mutation enter a population, they rapidly begin to take over the local epidemic, thus they are more transmissible.”
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Scientists at major organizations working on a vaccine or drugs have told The Times that they are pinning their hopes on initial evidence that the virus is stable and not likely to mutate the way influenza virus does, requiring a new vaccine every year. The Los Alamos report could upend that assumption.

If the pandemic fails to wane seasonally as the weather warms, the study warns, the virus could undergo further mutations even as research organizations prepare the first medical treatments and vaccines. Without getting on top of the risk now, the effectiveness of vaccines could be limited. Some of the compounds in development are supposed to latch onto the spike or interrupt its action. If they were designed based on the original version of the spike, they might not be effective against the new coronavirus strain, the study’s authors warned.
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Even if the new strain is no more dangerous than the others, it could still complicate efforts to bring the pandemic under control. That would be an issue if the mutation makes the virus so different from earlier strains that people who have immunity to them would not be immune to the new version.

If that is indeed the case, it could make “individuals susceptible to a second infection,” the study authors wrote.