I instantly (and incorrectly) assumed that this was some conspiracy theory-laden story about how big pharma doesn't want to stop cocaine use and the war on drugs is too profitable and etc. etc. etc., but thankfully I was wrong. Here's the key line from the story:
the dilemma is clear: What would happen if the media got
wind that inoculated drug users were buying even more coke
than before. It would be a public relations nightmare for
any business.
So that's it - and it makes sense. Vaccine makes cocaine less effective, so people buy more (in the short term) to try and get the same high, until they finally realize that doesn't work and give up using it. Long term good, short term PR nightmare.
The problem is that patiens on the vaccine would have higher risks of overdose because they now take so much more cocaine. Also I wonder what percentage of them would try to switch to some other drugs.
I think the best case for this vaccine is a therapy with vaccine and a supporting group or counsel, and this is made more for people trying to give up the habit (dependency) or for people not to start.