Vaccines are usually seen as fighting infectious diseases, but what about a vaccine for addiction? HHS Secretary Tom Price says one is being developed but experts say such a shot is not likely in the near future.

Price, who has been looking for ways for the FDA to fight the opioid crisis, offered some hope for such treatment during a White House press session about the current situation.

"One of the things they're actually working on is a vaccine for addiction, which is an incredibly exciting prospect," Price said referring to research being done at the NIH.

But one expert said that treatment option has a long way to go. "I can't imagine the vaccine would be on the market before the Trump administration is over,"  Thomas Kosten, M.D., professor of psychiatry at Baylor College of Medicine told CNN. 

Like other vaccines, a vaccine for addiction would be aimed at eliciting antibodies, although in this case they would be acting against the toxic drugs. While it is possible in concept, it still needs to get through all phases of clinical tests before reaching the market and Kosten understands the difficulty of reaching that milestone.

Kosten previously led a team of scientists that was studying a therapeutic cocaine vaccine called TA-CD developed by U.K. company Xenova. The vaccine was designed to stimulate antibody response to stop the cocaine from getting from the blood into the brain, thereby removing the euphoric experience from taking the drug.

That vaccine failed in a phase 3 clinical trial as it didn’t show significant improvement in getting trial subjects off the drug, even when adequate antibody levels were attained. The trial also shed some light on how an anti-addiction vaccines could be counterproductive.

At a certain point during the study, patients with higher antibody levels had even more cocaine-positive urine.

"We are concerned that adequately immunized subjects may have increased their cocaine use to overcome the competitive anticocaine antibody blockade," wrote Kosten’s team in a 2014 study published in the journal Drug and Alcohol Dependence.

As for opioids, no vaccine has entered the clinic, Kosten told CNN. But California-based Opiant Pharmaceuticals, previously known as Lightlake Therapeutics, which focuses on substance abuse treatments, recently in-licensed a heroin vaccine developed by the Walter Reed Army Institute of Research in collaboration with the National Institute on Drug Abuse (NIDA) under the NIH.

The vaccine is still in preclinical development, and it is designed with a similar mechanism to TA-CD—trying to generate antibodies that block morphine from binding to opioid receptors in the brain to remove the "high" factor.

"It's a long process, and it takes years," Ivan Montoya, M.D., acting director of the Division of Therapeutics and Medical Consequences at the NIDA, said of the vaccine development endeavor, as quoted by CNN. He said that maybe Price "saw the mechanism and got excited about the approach."

In April, NIH Director Francis Collins, M.D., Ph.D., met with leading biopharma companies and formed a public-private alliance to address the opioid epidemic. A key area of focus of that partnership, as laid out in a New England of Journal article, is centered on advancing new and innovative medication and biologics to treat opioid addiction and for overdose prevention and reversal.