Saudi Arabia COVID variant, should we be concerned?

This study out of Saudi Arabia is reporting a newly discovered type of variant circulating there. All of the variants of concern that have gotten attention so far involve key mutations in the spike protein that allow the virus to bind more tightly to cells, or destabilize the spike so that it facilitates more efficient entry into cells, or allow the spike to evade the immune response from prior infections.

This mutation is in the nucleocapsid protein. My expertise is much more in the direction of the spike protein, but in general, I can tell you that nucleocapsid is a protein inside of a membrane-bound virus that binds to and protects the viral genome. It also binds to RNA inside of the cell after infection happens and can alter gene expression of the cell.

The mutation in the nucleocapsid (R203K/G204R) appears to have been around for most of the pandemic, and is just now being noticed as a mutation of interest. In Saudi Arabia, it is associated with increased viral load. It is also associated with increased death, although their numbers for that are not quite large enough for statistical significance. It changes the gene expression inside of cells a little bit relative to the original nucleocapsid.

I don't think that this is cause for panic. The vaccines work by targeting the spike protein, so this mutation should not affect vaccine efficacy. And it's been around for awhile. It probably partially explains why some people have had more severe or more contagious covid all along.

Link to study: https://www.medrxiv.org/content/10.1101/2021.05.06.21256706v1.full.pdf