Question: In response to yesterday, Yikes! So, would the vaccines currently in development stages work against the G strain? Or only for the D strain?

Answer: One clarification from yesterday that’s related to your question and then the answer to your question. In short, we expect viruses to mutate. So far, the mutations of SARS-CoV-2 have been slow and not too dramatic, which means that vaccines in development now are more likely to be effective when rolled out [early next year, fingers crossed].

SARS-CoV-2 Strains

We’ve known about the G strain for some time (since March, which is a long time in the scheme of knowing things about SARS-CoV-2). And Vietnam has previously experienced cases from the G strain. As stated by the Minister of Health in late-July, and as the GISAID database confirms, Vietnam has previously recorded five strains (aka clades) among confirmed cases. Apparently, what’s come up in Vietnam is a sixth strain. Unfortunately, I haven’t found information about what this strain is. We do know — thanks to the GISAID database and this recent study published in Frontiers in Microbiology — that there are six major strains of SARS-CoV-2. Study authors report, “Currently, the G clade and its offspring, GH and GR, are the most common clades amongst the sequenced SARS-CoV-2 genomes, globally accounting for 74% of all world sequences. Specifically, the GR clade, carrying the combination of Spike D614G and Nucleocapsid RG203KR mutations, is currently the most common representative of the SARS-CoV-2 population worldwide. The original viral strain, represented by clade L, still accounts for 7% of the sequenced genomes, and the other derived clades S and V have similar frequencies in the global dataset.” So I’m not sure whether the Vietnam strain is one of these or a different strain. Check out Figures 1 and 2 to see the viral clades over time and by geography (note: O= others).

Vaccines

Good news is that scientists are still observing that SARS-CoV-2 is slow to mutate. Molecular biologist, Dr. Peter Thielen, recently described on NPR’s All Things Considered that “viruses circulating today look remarkably similar to the ones that appeared in China late last year…The targets for diagnostics and the targets for vaccine design still today remain the same as we would’ve designed them in January.” Similarly, biologist Dr. Benjamin Neuman recently told Healthline, “The virus is still so similar now to the initial sequence that there isn’t really much reason to think the differences will matter in terms of vaccine.”

Figure 1. SARS-CoV-2 Strains Over Time (from GISAID)

Figure 2. Recent Distribution of SARS-CoV-2 Strains by Country (from GISAID)