Addiction Vaccines: Fact or Fiction?

By Martin Buxton, MD, Psychiatrist and Addictionologist, Pinnacle Treatment Centers

The development of vaccines to prevent deadly or debilitating diseases is considered one of the greatest accomplishments in modern medicine. In fact, vaccines may be one of humankind’s greatest accomplishments, period.

The number of lives saved and the amount of human suffering vaccines prevent each year is staggering. Diseases that were once a death sentence can now be avoided altogether. Diseases that once caused permanent disability are no longer a threat – as long as we’re properly vaccinated and receive boosters on a schedule recommended by medical professionals.

To get an idea of the impact of vaccines on human health, we offer the following information on the overall effectiveness of vaccines in the 20th century. This list includes annual fatality rates of deadly diseases before the introduction of vaccines during the early/mid-20th century, and the projected fatality rates for the same diseases at the end of the 20th century. This data, limited to the U.S., was collected and published by the Centers for Disease Control (CDC) in 1998, based on historical and contemporary data. They’re the best estimates possible, given the information available to scientists at the time.

  • Smallpox:
    • Before vaccine: 48,164
    • After vaccine: 0
  • Diphtheria:
    • Before vaccine: 175,000+
    • After vaccine: 1
  • Pertussis (Whooping Cough)
    • Before vaccine: 147,000
    • After vaccine: 6,279
  • Tetanus:
    • Before vaccine: 1,314
    • After vaccine: 34
  • Polio:
    • Before vaccine: 16,316
    • After vaccine: 0
  • Measles:
    • Before vaccine: 503,202
    • After vaccine: 89
  • Mumps:
    • Before vaccine: 152,209
    • After vaccine: 606
  • Rubella:
    • Before vaccine: 47,745
    • After vaccine: 345

Note: In 2000, measles was declared eliminated in the United States. However, in 2018-2019, measles outbreaks in the U.S. threatened this status. The main reason for the reappearance of measles in the U.S. is the refusal of some families to vaccinate their children against measles.

Vaccines Save Lives – But Can They Work for Addiction?

Some quick math with the numbers above shows that in the U.S., vaccines saved tens of millions of lives in the 20th century. Data from the World Health Organization (WHO) shows that vaccines likewise saved hundreds of millions of lives since their introduction and widespread dissemination. Most people aren’t aware that the Spanish Flu epidemic of 1918 resulted in an estimated 20-50 million deaths worldwide, with close to 675,000 deaths in the U.S. – many of which could have been prevented with the flu vaccine resources available today.

That’s why there’s such interest in developing a vaccine for addiction. And it’s not just theory: scientists have been working on addiction vaccines since the 1970s. The current opioid epidemic has reinvigorated the effort.

In the words of Dr. Tom Price, then secretary of The Department of Health and Human Services, after a high-profile White House proclamation on efforts to curb opioid addiction in 2017:

“One of the things they’re actually working on is a vaccine for addiction, which is an incredibly exciting prospect.”

Exciting, indeed. With close to 22 million people in the U.S. over the age of 12 struggling with an alcohol or substance use disorder, and estimated relapse rates ranging from 20%-80%, the idea of preventing addiction with an injection sounds too good to be true. Things that sound too good to be true typically are just that.

But the basic science behind addiction vaccines is rock-solid.

Immunity and Vaccines: The Basics

In theory, addiction vaccines would work the same way all vaccines do. They’d leverage the immense power of the body’s immune system. Here’s a quick refresher on how immunity works:

  1. A disease enters the body in the form of a virus or bacteria.
  2. Immune cells recognize the foreign body – known as an antigen – as potentially harmful.
  3. The immune system then creates antibodies – little proteins – specific to that antigen.
  4. The antibodies attach to the antigen, labeling it for destruction by specialized immune cells that roam the body.
  5. When a new antigen enters the body, it takes the immune system several days to develop antibodies and fight the disease. However, once the body develops antibodies for a disease, they’re stored in memory cells, which can quickly reproduce antibodies when the antigen is reintroduced to the body. This ability to quickly react and repel foreign invaders is what we think of as immunity.

Vaccines take advantage of our immune system by exposing the body to antigen designed to provoke just enough of an immune response to cause the body to create antibodies, but not actually contract the disease. The immune system then creates memory cells for those antibodies, and the next time the body is exposed to the antigen, it’s ready to fight back. That’s how, in the 20th century, we drastically reduced or eliminated all the infectious diseases mentioned above.

How an Addiction Vaccine Would Work

An addiction vaccine would work much the same way all other vaccines work: it would teach the immune system to recognize, react to, and eliminate antigen from the body. But since the human immune system does not recognize alcohol or drugs of abuse as antigen – i.e. foreign invaders or diseases – scientists have to take extra steps to trick the body into recognizing the target drug as antigen so that it will then create protective antibodies.

It’s a two-step process.

First, they change the target molecule (the drug) into what’s called a hapten. Second, they attach a larger molecule to the hapten. This molecule does two things: it identifies the drug as antigen, ready to be destroyed by the immune system, and prevents it from crossing the blood/brain barrier, which blocks its euphoric effects, thereby eliminating the high people experience when taking substances of abuse. Have a look at this CDC tutorial for an animated version of how a successful addiction vaccine would work.

So, since the science behind vaccines for addiction is sound, why don’t we have them?

Addiction Vaccines: Overcoming Obstacles

There are many reasons we don’t have addiction vaccines yet, but they can be distilled into three major categories:

  1. Scientific/Medical.

Challenge 1: Since people develop addictions to many different substances, from alcohol to opiates to marijuana to amphetamines, scientists need to develop a different hapten/molecule combination for each drug of abuse.

Challenge 2: The hapten/molecule combination has to be potent enough to generate an adequate immune response. In the 1970s, researchers created sufficient antigen to nicotine, but in human trials the vaccine did not people quit smoking.

Challenge 3: Currently, addiction vaccines in trials are only effective for 2-3 months. Booster shots would be needed several times a year for them to be effective.

  1. Financial.

Challenge 1: Human testing for vaccines is very expensive, potentially costing hundreds of millions of dollars per vaccine, with no guarantee of success.

Challenge 2: Government programs from the Department of Health and Human Services rarely support programs as costly as human vaccine trials.

Challenge 3: Private funding for medication research typically comes from pharmaceutical companies, but to date, they’ve been reluctant to support research for a medication that will only be taken 2-3 times per year, rather than daily.

  1. Human

Challenge 1: Vaccines for addiction will only work if someone wants to achieve sobriety, because – when they’re developed – they will require frequent booster doses. If someone wants to use alcohol or drugs, they’ll simply skip their shot, and their drug of choice will work again.

Challenge 2: To date, all addiction vaccines can be rendered useless by overwhelming them with large amounts of the target drug. If someone wants to get high while the vaccine is still active in their system, they can: they just need to take more of the drug.

Challenge 3: The stigma around addiction in our society is powerful. Many people – often those with substance use disorders themselves – see addiction as a moral failing or a lack of self-control. They’re neither open to the disease model of addiction, nor do they believe medication can cure what they perceive as a character flaw rather than a disease.

Despite these challenges, scientists are hard at work searching for viable addiction vaccines. The opioid crisis has renewed interest in allocating funding towards this effort, and the results are encouraging.

In recent years, studies on anti-heroin vaccines have shown promising results in non-human primate trials, studies on anti-cocaine vaccines have shown promising results in human trials, and finally, studies on a novel combination heroin/HIV-1 vaccine have shown promising results in mice. However, we’re still years away from an FDA-approved vaccine for any type of addiction.

Reality Check: There is No Magic Pill

The acceptance of addiction as a potentially relapsing medical condition is changing the way we, as a society, view addiction treatment. People now understand that a combination of medication, lifestyle changes, and behavioral therapy are effective in treating alcohol and substance use disorders, much in the same way medication, lifestyle changes, and behavioral changes are effective in treating other relapsing diseases such as hypertension, diabetes, and cancer.

However, this movement toward accepting the disease model of addiction comes with a danger. Where disease and illness are concerned, we have a quick-fix mentality: get sick, go to doctor, get medicine, take pills, get better. At this point in our understanding of medical science, it’s clear that treating substance use disorders will never be as simple as this prescribe and forget approach to which we’ve become accustomed.

Alcohol and substance use disorders affect the mind, body, and spirit. They change the way we think, feel, and behave. The longer the disorder lasts, the more severe the changes. They’re medical conditions, yes, but at the same time, they’re behavioral disorders that require a holistic approach to treatment.

The idea that we can heal the breadth of emotional, psychological, and physical dysfunction addiction causes with a single pill or injection contradicts everything we’ve learned from addiction science over the past 20 years. What we know is that recovering from an alcohol or substance use disorder takes an integrated approach that includes an individually tailored combination of therapy, medication (if needed), and ongoing social support.

If the evidence from the current generation of clinical trials shows vaccines to be effective in blocking the effects of drugs of abuse, then the best path forward will be to incorporate that vaccine into a comprehensive, integrated treatment plan that addresses the entire person – not just the effects of one chemical compound.

A vaccine won’t be a magic bullet – those are fiction, and don’t exist – but rather, another fact-based tool in our toolbox to help people struggling with addiction return to a state of health and wellness.