I’m not a virologist, an expert in how viruses work, or an epidemiologist, an expert in how human societies respond to them, but I can read a bit.
Why is the new S African variant likely to be more dangerous?
The rod-like spike proteins on the surface of SARS CoV-2 are the tip of the spear of the COVID-19 pandemic. The spikes bind to human cells via the ACE2 receptor and then dramatically change shape. They jack-knife, folding in on themselves to fuse their own membrane with the membrane of our cells. And that opens the door to coronavirus infection.https://answers.childrenshospital.org/sars-cov-2-spike-protein/
All of the current vaccines, other than the one developed in Scotland, ‘target’ the spike protein to trigger the immune system response, which can then destroy the virus.
The new S African variant has as many as 30 mutations to spike protein alone making it harder for the vaccine-induced immune response to recognise it until it is too late and infection has occurred.
Why is the Livingston Valneva vaccine likely to succeed even when the spike protein has mutated?
Rather than induce an immune response that targets just the spike protein of the coronavirus, the Valneva vaccine, also known as VLA2001, stimulates an immune response to the entire virus, and that might just give it an edge over its competitors.
It is different in that it uses the tried and tested method of taking the whole of the coronavirus and inactivating it so that it can no longer cause illness.https://www.aljazeera.com/features/2021/11/9/valneva-covid-19-vaccine-why-it-might-be-a-game-changer
Corrections and clarifications welcomed, of course.