neb:neb: For more depressing news, 'No Evidence' Yet That Recovered COVID-19 Patients Are Immune, WHO Says. Although it does support most countries' position of not gambling on the herd immunity approach.
Anyone know what this does this do for the prospects of a vaccine if exposure doesn't build immunity?
Imo this is a complex answer and depends which mechanism is used, and depends exactly what any particular vaccine chooses as it's target(s). There are several in development.