So quickly, in fact, a new sequence initially identified in the United Kingdom, then Europe and now Texas, has again captured the attention of leading virologists.
This particular strain, known as a D614G mutation, was responsible for 99.9% of cases staffing Houston’s second wave a couple of months back.
Although D614G does not appear to result in more severe manifestations of COVID-19, it is believed to be much more contagious.
A Gly614 amino acid replacement in SARS-CoV-2’s spike protein is purported to account for the mutation’s improved transmissibility.
“The genomes were from viruses recovered in the earliest recognized phase of the pandemic in Houston, and an ongoing massive second wave of infections. The virus was originally introduced into Houston many times independently,” researchers recently explained in the medRxiv journal.
In the short time since the medRxiv report, independent sources have speculated about the mechanisms energizing the D614G mutation.
It’s true that RNA viruses mutate much more regularly compared to DNA viruses but this latest mutation may be a response to global countermeasures. Currently, the very best masks block roughly 99% of viral particles.
In order to infect a greater share of host cells, genetic errors need to correct key limitations within the novel coronavirus. By causing the host to shed more viral debris, the pathogen can even the odds in light of masks and social distancing.
“Wearing masks, washing our hands, all those things are barriers to transmissibility or contagion, but as the virus becomes more contagious, it statistically is better at getting around those barriers,” David Morens, a virologist at the National Institute of Allergy and Infectious Diseases said in a media release.
He added that if this mutation permeates it “may have implications for our ability to control it.”
These are important elements for officials to digest as we enter winter. Many establishments are preparing to host patrons indoors at 25% capacity at the end of the month.
Recent data sets seem to argue against a fool-proof response to the COVID-19 pandemic. In other words, there isn’t just one element, clinical or otherwise, that will negate the need for caution anytime soon.
“The vaccine availability will go a giant step to controlling the infection, but you’re not going to completely eradicate it or eliminate it,” Dr. Anthony Fauci recently remarked on the back of a report signaling a vaccine by the end of October.
With a series of macropolitical events between now and then, we may see stricter precautions implemented nationwide. At the very least, regions linked to Gly614 and D614G variants would do well to keep track of revised health guidelines.
“Patients infected with the Gly614 variant strains had significantly higher virus loads in the nasopharynx on initial diagnosis. We found little evidence of a significant relationship between virus genotypes and altered virulence, stressing the linkage between disease severity, underlying medical conditions, and host genetics,” the authors concluded. “Some regions of the spike protein – the primary target of global vaccine efforts – are replete with amino acid replacements, perhaps indicating the action of selection. We exploited the genomic data to generate defined single amino acid replacements in the receptor-binding domain of spike protein that, importantly, produced decreased recognition by the neutralizing monoclonal antibody CR30022.”