Five months after China first reported the coronavirus, a new study suggests that a more infectious strain of the novel coronavirus is already roaming Earth. They found that it is the dominant version of SARS-CoV-2- the virus that causes COVID-19.
Researchers say that a mutation concerning the region on the virus that binds to human cells makes the virus more contagious. But that does not mean that it is deadlier than the original strain first discovered in Wuhan.
Now, the race of creating the vaccine against the deadly virus is on. But could this mutated version of coronavirus affect the efficacy of any of the existing COVID-19 vaccine candidates that are in development or human trials?
The dominant version of SARS-CoV-2
Just a couple of weeks ago, a research said that the SARS-CoV-2 is not mutating as fast as the flu virus, and the mutations recorded are not noteworthy. That is good news for a vaccine candidate against COVID-19 because an effective drug could induce long-lasting immunity and prevent infection.
However, a new study claims that the virus has developed significantly that it makes it even more infectious than the original strain. Presently, that strain becomes the dominant one roaming around the planet, which explains the massive surge of infected people over the past few months.
But according to the researchers, a more infectious disease does not necessarily mean that it is more deadly than the original. However, it could possibly affect the vaccine candidates that are made to target the milder form of the disease, as there is no guarantee that they will work against the more potent strain.
On the other hand, those vaccine candidates who have already reached its human trials will come in contact with the mutated version of the virus and would be able to prove its efficacy against it, reported BGR.
The researchers from the Los Alamos National Laboratory published their research in BioRxiv in pre-peer-review form. This means that their study requires more validation from colleagues.
According to their paper, the new strain appeared in February in Europe, then migrated to the East Coast and has since become the dominant strain across the world in March. The researchers looked at the evolution of the virus and found a mutation on the spike protein, which is the component that hooks to ACE2 receptors where it can take over the cell and replicate.
A mutation on the spike protein of the virus
The researchers studied more than 6,000 SARS-CoV-2 sequences from all over the world, and they found out that the mutated version was transitioning to become more dominant. Out of 14 mutations identified, D614G concerns the scientists the most as it is responsible for a change in the spike of the virus.
"D614G is increasing in frequency at an alarming rate, indicating a fitness advantage relative to the original Wuhan strain that enables more rapid spread," the study said the researchers.
Furthermore, they noted that the new strain infected far more people than earlier strains, and just within weeks, it has become the only prevalent novel coronavirus found in some countries. This proves that compared to its predecessors, this new strain is more infectious.
Interestingly, a mutation on the virus' spike was also mentioned in a separate study conducted by researchers from Australia and Taiwan. However, it is still uncertain whether they observed the same mutation.
The study did not indicate why this mutation makes the virus more infectious and why people infected with it seem to have higher viral loads. In a worst-case scenario, this mutated virus could bypass the host immunity and reinfect patients the second time, just as the case with the flu. Teams developing the vaccines will likely take these mutations into account.