“I’ve always wondered why they chose the spike protein part instead of the nucleocapsid protein part.”
Because the S-protein is on the outside and the N-protein is on the inside.
Duh
Well you’re full of sh*t as per usual. A vaccine using the nucleocapsid is a viable alternative to using the spike protein.
Nucleocapsid as a next-generation COVID-19 vaccine candidate
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9250828/