> The cancer vaccine: Moderna and pharma giant Merck are developing an mRNA-based cancer vaccine, mRNA-4157 (V940), for people who’ve had high-risk melanomas removed.
This is still treatment. They aren’t administering the vaccine to healthy adults. The population is melanoma survivors with a high risk of recurrence.
It's not a generally-distributed vaccine, but there are all sorts of vaccines that aren't generally distributed and instead applied only to populations likely to encounter the illness protected against (such as the battery one is exposed to if one travels to particular parts of the world).