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Local COVID-19 strains

We did some full genome sequencing. We have sequenced and shared up to 15 COVID-19
isolates in the GISAID database. This includes the viruses isolated from the first wave and
second wave. When we looked at the phylogenetic analysis of the samples of SARS-CoV-2
full-genome sequences, we found that most of the local COVID-19 strains were from strains
B and C.

Strain B can be divided into B ancestral strains and B derived strains. The B ancestral strains
came from Wuhan and it is closely related to Wuhan strain. Initially, it was B ancestral strain
and it passed on to a lot of people. Because it is a RNA virus, it will mutate as it passes from
person-to-person becoming B derived strain. From the first generation, it can mutate to the
second generation and to the third generation and so on. We will see a lot of mutations. We
also see a distinct branching out of strain C, which was mainly from Europe and Singapore
and also some local cases from Sri Petaling gathering.

We are fortunate as we didn’t find any distinct mutation such as D614G mutation which is
based on spike protein. There are some papers looking at D614G mutation. This gene
mutation has been associated with high transmissibility. Some papers reported antibodies
found in patients who had been infected with earlier forms of the SARS-CoV-2 pathogen
failed to neutralize the D614G mutated strain.