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FEATURE
GENEWS
October 2020
D614G Mutation in SARS-CoV-2 detected in the by JUSTIN BADLIS (Crypton) Philippines
T
he Philippine Genome Center (PGC) has reported the detection of the SARSCoV-2 variant known as the D614G from 9 samples collected from the Philippine General Hospital in Quezon City this July 2020. The presence of spikes surrounding the virus core characterize the coronaviruses. These spikes enable the virus to attach to Angiotensinconverting enzyme 2 (ACE2) receptors present in epithelial cells of many organs, including the lungs, heart, and the kidneys. Mutations are a part of the natural cycle viruses. This reported mutation occurred from the spike protein amino acid change originally from the D614 form. The SARS-CoV-2 virus was originally of the D614 variant, and studies reported how it completely replaced the G614 variant in Europe and the Americas. The PGC however emphasizes that this detected mutation may not reflect mutational spread of the SARS-CoV-2, and just merely confirms G614. But what does this imply on our current situation on the ongoing pandemic? What do we know? Recent studies hypothesize that this variant of more competitive
than the original virus from China. A study by Zhang et al. explained that the spike protein reduces S1 shedding (the S protein domain that mediates receptor binding), which increases infectivity. In vitro studies also suggest that the D614G mutation seem to have higher levels of viral RNA1 which may contribute to its infectivity. However, scientists urge that there is still no clear mechanism whether the variant is more transmissible than the D614. A study by Grubaugh and colleagues that the predominance of G614 in other areas are a product of chance, stating that the introduction of D614 from China declined, whereas the G614 predominant in Europe climbed. The same study also suggests that as of now, there is still no conclusive evidence whether the D614G variant is more transmissible, and whether it is harder to control. Should we be concerned? Studies link The D614G mutation to an increased infectivity, but whether it has a notable effect to its hosts remains unclear. There exists the demand for further studies on its mechanism, such as its adaptation to human ACE2 receptors and the observable effects on animals. But overall, mutations such as D614G have not made it more deadly.
Vaccine development relies on the tracking and study of mutations the virus undergoes during its spread. Its effectivity should encompass every mutation a virus develops; thus, coronavirus vaccines should work equally on all variants. A preprint study by Shi et al. suggests that the mutation may not reduce the ability of vaccines in clinical trials, and vaccine developers should test therapeutic antibodies on the G614 virus before clinical development. Zhang and colleagues also state that vaccines would most likely work D614G viruses. Most mutations in viruses are not disconcerting, as it is natural in a virus life cycle and rarely becomes a big deal. If ever, mutations may lead to weaker versions of the virus. Discoveries of mutations provides us information on the patterns of spread which may lead to the formulation of methodologies that could limit its spread. It is unlikely that these mutations would result to increased mortality. As of October 11, 2020, the Philippines has 339,341 COVID-19 cases, with a bulk of these coming from the NCR. This number of cases brought us among the top 18 countries with most reported cases worldwide.
