175 CMAAO CORONA FACTS and MYTH COVID
Dr K Aggarwal
With inputs from Dr Monica Vasudev
SARS-CoV-2 virus shows
little variability regardless of mutations
Daily): SARS-CoV-2 mutation rate remains low. Across Europe and Italy, the most
widespread is strain G, while the L strain from Wuhan is gradually
disappearing. These mutations, however, do not impinge on the process of
developing effective vaccines.
virus causing the COVID-19 pandemic, SARS-CoV-2, presents at least six strains.
Despite its mutations, the virus shows
little variability, and this is good news for the researchers working on a
are the results of the most extensive study ever carried out on SARS-CoV-2
at the University of Bologna drew from the analysis
of 48,635 coronavirus genomes, which were isolated by researchers in labs
all over the world. This study was published in the journal Frontiers in Microbiology. It was then possible for researchers
to map the spread and the mutations of the virus during its journey to all
first results are encouraging. The
coronavirus presents little variability, approximately seven mutations per
Common influenza has a variability
rate that is more than double.
SARS-CoV-2 coronavirus is presumably already optimized to affect human beings,
and this explains its low evolutionary change," explains Federico Giorgi,
a researcher at Unibo and coordinator of the study. "This means that the
treatments we are developing, including a vaccine, might be effective against
all the virus strains."
Currently, there are six strains of
- The original one is the L strain that appeared in Wuhan in
first mutation -- the S strain -- appeared at the beginning of
- Since mid-January 2020, we have
had strains V and G.
- To date strain G is the most
widespread: it mutated into strains
GR and GH at the end of February 2020.
G and its related strains GR and GH are by far the most widespread,
representing 74% of all gene sequences we analysed," says Giorgi.
"They present four mutations, two of which are able to change the sequence
of the RNA polymerase and Spike proteins of the virus. This characteristic
probably facilitates the spread of the virus."
we look at the coronavirus map, we can see that strains G and GR are the most
frequent across Europe and Italy. According to the available data, GH strain
seems close to non-existence in Italy, while it occurs more frequently in
France and Germany. This seems to confirm the effectiveness of last months'
In North America, the most widespread
strain is GH, while in South America we find the GR strain more frequently.
In Asia, where the Wuhan L strain
initially appeared, the spread of strains G, GH and GR is increasing.
strains landed in Asia only at the beginning of March, more than a month after
their spread in Europe.
Globally, strains G, GH and GR are
constantly increasing. Strain S can be found in some restricted areas in the US
and Spain. The L and V strains are gradually disappearing.