An increasingly common mutation of the novel coronavirus found in Europe, North America and parts of Asia may be more infectious but appears less deadly, according to a prominent infectious diseases doctor.
Paul Tambyah, senior consultant at the National University of Singapore and president-elect of the International Society of Infectious Diseases, said evidence suggests the proliferation of the D614G mutation in some parts of the world has coincided with a drop in death rates, suggesting it is less lethal.
"Maybe that's a good thing to have a virus that is more infectious but less deadly," Tambyah told Reuters.
Tambyah said most viruses tend to become less virulent as they mutate.
"It is in the virus' interest to infect more people but not to kill them because a virus depends on the host for food and for shelter," he said.
Scientists discovered the mutation as early as February and it has circulated in Europe and the Americas, the World Health Organization said. The WHO also said in July that there is no evidence the mutation has led to more severe disease. (https://reut.rs/3kThRr3)
The D614G mutation has been shown to increase the number of protein spikes on the virus surface and also to make them more stable (bit.ly/3e5ufAy). That may also increase the virus' susceptibility to spike-targeted vaccines, one study suggests (bit.ly/39vmRNr).
However, there is still no evidence that the mutation affects virulence for better or worse. Most experts have attributed reduced death rates relative to earlier stages of the pandemic to the fact that the virus is increasingly infecting younger, healthier people.
On Sunday, Malaysia's director-general of health Noor Hisham Abdullah urged greater public vigilance after authorities detected what they believe was the D614G mutation of the coronavirus in two recent clusters.
Sebastian Maurer-Stroh of Singapore's agency for science, technology and research said the variant has also been found in the city-state but that containment measures have prevented large-scale spread.
Malaysia's Noor Hisham said the D614G strain detected there was 10 times more infectious and that vaccines currently in development may not be effective against this mutation.
But Tambyah and Maurer-Stroh said such mutations would not likely change the virus enough to make potential vaccines less effective.
"(The) variants are almost identical and did not change areas that our immune system typically recognise, so there shouldn't be any difference for vaccines being developed," said Maurer-Stroh.
(This story corrects to say National University Hospital in second paragraph )
