"variants slightly change the shape of the spike protein."
https://www.thesun.co.uk/news/15782798/warning-doomsday-covid-variant-us-map/
"Mutations in the spike protein are also what determine different variants of SARS-CoV-2, and can alter its ability to infect and cause harm."
https://sciencebasedmedicine.org/spike-proteins-covid-19-and-vaccines/
"The variant in question, D614G, makes a small but effective change in the virus’s ‘Spike’ protein, which the virus uses to enter human cells."
https://www.lanl.gov/updates/sars-cov-2-variant.php
"Alpha variant (B117), the study confirms that a genetic change in the spike (a single amino acid substitution) helps the virus bind better to ACE2 receptors, making it more infectious"
https://m.timesofindia.com/home/science/spike-protein-changes-in-covid-variants-can-make-vaccine-ineffective/articleshow/83867094.cms
"single base mutation is sufficient to program the virus to change amino acid #614 from aspartic acid (D) to glycine (G) and give the world the lovely gift of D614G; hence, delta COVID."
https://www.acsh.org/news/2021/07/27/1-molecule-vinegar-and-voila-delta-variant-15687
"new mutations that alter how the spike functions are of particular concern – they may impact how we control the spread of SARS-CoV-2. The new variants found in the UK and elsewhere have mutations across spike and in parts of the protein involved in getting inside your cells"
https://news.yahoo.com/coronavirus-variant-spike-protein-why-160220955.html
"The advanced proteins on the surface of SARS CoV-2 allow the virus to attach and invade our cells, and all current vaccines are directed against them."
https://www.archyde.com/changes-to-the-spike-protein-in-covid-variants-can-make-vax-ineffective-health-info-pta-professional/
Spike Protein Changes in COVID Variants Can Make Vaccine Ineffective
https://www.ibtimes.sg/spike-protein-changes-covid-variants-can-make-vaccine-ineffective-58435