[euthymiclabs]

It's provocative in rats, but there's lessons from similar attempts that need to be considered. Cocaine-specific vaccines have been in development for years, and they haven't been successful. The biggest problem is that you need people to maintain an enormous concentration of antibodies against the drug so that even minute quantities are captured within seconds of entering the blood stream. Even if you can achieve an initial therapeutic levels, you need to constantly boost the vaccine to maintain high antibody titer. All of these attempts have targeted people with cocaine use disorder and are able to focus on shots every few weeks to months. We're nowhere close to developing something that would work as a routine preventative vaccination.

We do have a once a month injection of naltrexone that can block all opioids, which can be effective in the right person. A targeted approach to fentanyl alone would probably work in people who don't have an opioid use disorder (and therefore wouldn't be as prone to substitution with an alternative opioid). This is an interesting step, but our understanding of immunology is far too limited to make this realistic in the near term.