Virus mutation is a process during replication (growth) of a virus where changes occur in its genetic make-up. A mutation can be beneficial or deleterious to a virus’ growth or may have no impact at all.
Since the beginning of the Covid-19 pandemic, scientists have been discussing different effects of virus mutation and declaring it one of the options for ending the Covid-19 pandemic, like SARS (a previous coronavirus disease), which disappeared in 2003 due to mutations in a previous coronavirus.
Interestingly, a specific strain of the current coronavirus (officially SARS-CoV-2) which had a mutation in the D614G region of virus spike protein (which helps it to enter human cells), appears to be spreading, with latest outbreaks in Southeast Asia.
The name D614G means a change in amino acid from D (aspartic acid) to G (glycine) at position 614 of the coronavirus. Recent data suggest that having this mutation has become the most widespread strain globally.
The virus originated in Europe and then came to Southeast Asia after natives returned to their countries from Europe. The important aspect of this mutation is that it has made the virus more infectious but less deadly, according to some reports.
Dr Paul Tambyah, a senior consultant of National University of Singapore reported that there are studies showing propagation of D614G mutation in different parts of the world with a decrease in death rates which indicates that it is less lethal. As he said, “maybe that’s a good thing to have a virus that is more infectious but less deadly”.
Usually, viruses like to become less virulent as they mutate because it is in the interest of the virus to infect more people without killing them as it depends on its host for food and shelter. According to WHO, this mutation has spread in Europe and the US, but no evidence has been found to relate it with the severity of Covid-19.
Noor Hisham Abdullah, director general of health in Malaysia, reported the detection of a coronavirus with a D614G mutation in two recent clusters in Malaysia. He said that coronavirus with a D614G mutation is 10 times more infectious than the original strain isolated in Wuhan.
Many vaccines against the coronavirus are in clinical phases. As these vaccines target the spike protein of coronavirus, there are some concerns regarding their effectiveness on this D614G mutation.
Although, this mutation exists in the spike protein, vaccines are targeting different regions of the spike proteins which are important for our immune system. Therefore, there are fewer chances that this mutation will result in a vaccine failure.
The author is assistant professor at the Department of Biology,
University of Bahrain