Meth vaccine shows promising results in early tests

November 1, 2012
Scripps Research Institute Associate Professor Michael Taffe, Research Associate Michelle Miller, and colleagues have developed a promising vaccine against a methamphetamine high.

Scientists at The Scripps Research Institute (TSRI) have performed successful tests of an experimental methamphetamine vaccine on rats. Vaccinated animals that received the drug were largely protected from typical signs of meth intoxication. If the vaccine proves effective in humans too, it could become the first specific treatment for meth addiction, which is estimated to affect 25 million people worldwide.

"This is an early-stage study, but its results are comparable to those for other drug vaccines that have then gone to clinical trials," said Michael A. Taffe, an associate professor in TSRI's addiction science group, known as the Committee on the Neurobiology of . Taffe is the senior author of the study, which is currently in press with the journal Biological Psychiatry.

A Common and Dangerous Drug of Abuse

Over the past two decades, has become one of the most common drugs of abuse around the world. In the United States alone there are said to be more than 400,000 current users, and in some states, including California, meth accounts for more primary admissions than any other drug. Meth has characteristics that make it more addictive than other common drugs of abuse, and partly for this reason, there are no approved treatments for meth addiction.

In recent years, scientists at TSRI and other institutions have taken the innovative approach of developing vaccines against . These vaccines evoke against , just as traditional vaccines evoke antibody responses against viruses or bacteria. Anti-drug antibodies are meant to grab hold of drug molecules and keep them from getting into the brain—preventing the drug from giving the user a high and removing the incentive for taking the drug.

Vaccines against nicotine and cocaine are already in clinical trials. Some meth vaccines have been tested in animals, but generally with unpromising results. The methamphetamine molecule is structurally simple, making it relatively unnoticeable to the immune system. Meth and its main metabolite, ordinary amphetamine, also tend to linger once they get into the nervous system, so that even a little drug goes a long way. "The simple structure and long half-life of this drug make it a particularly difficult vaccine target," said Kim Janda, the Ely R. Callaway, Jr. Professor of Chemistry and member of the Skaggs Institute for Chemical Biology at TSRI.

'Encouraging Results'

Two years ago Janda and his laboratory developed six candidate meth vaccines. In each, the main active ingredient was a chemical cognate of the methamphetamine molecule—that otherwise would be too small to evoke any antibody response—linked to a larger, antibody-provoking carrier molecule. Early tests in mice indicated that three of these vaccine candidates could evoke a strong antibody response to meth. Taffe's laboratory later tested these three vaccines in rats and found the one, designated MH6, that worked best at blocking two typical effects of meth—an increase in physical activity and a loss of the usual ability to regulate body temperature.

In the new study, members of Taffe's laboratory, including Research Associate Michelle L. Miller, who was lead author of the study, investigated the MH6 vaccine in more depth. Using a different experimental setup, they found again that it prevented a rise in body temperature and burst of wheel-running hyperactivity that otherwise occur after meth exposure. Underlying these promising effects on behavioral measures was a robust antibody response, which in vaccinated rats kept more of the drug in the bloodstream and out of the nervous system, compared to control rats. "These are encouraging results that we'd like to follow up with further animal tests, and, we hope, with clinical tests in humans some day," said Miller.

"I think that this vaccine has all the right features to allow it to move forward in development," said Janda. "It certainly works better than the other active vaccines for meth that have been reported so far."

The Next Big Challenge

A separate group of researchers has reported promising animal test results for an antibody-based treatment. In this approach, the anti-meth antibodies are grown in cultured cells using standard biotechnology methods and then injected into the animal in a concentrated dose, preventing a meth high. Antibody-based therapies are commonly used to treat cancer and chronic immunological conditions. But they are typically expensive, costing thousands of dollars per dose, and the effects of a dose last for a few weeks at most. A meth treatment probably would have to be much more cost-effective to be widely useful, as addicts frequently have little money and no health insurance and receive their treatments from government health services.

In principle, an active vaccine would be cheap to make and administer and would confer protection for months per dose, rather than weeks with conventional monoclonal antibody therapy. In practice, active meth vaccine candidates don't yet last that long; for example, the MH6 candidate in the current study was given in four doses over 12 weeks. But Janda and Taffe believe that with further adjustment, an active meth vaccine could sustain an anti-meth antibody response for a much longer period.

"Extending the duration of protection is the next big scientific challenge in this field," said Taffe.

Explore further: Meds can help recovering meth addicts stay sober

More information: "A Methamphetamine Vaccine Attenuates Methamphetamine-Induced Disruptions in Thermoregulation and Activity in Rats," www.biologicalpsychiatryjourna … (12)00803-7/abstract

Related Stories

Meds can help recovering meth addicts stay sober

June 14, 2012
(Medical Xpress) -- A drug shown to help break alcohol addiction can also help recovering methamphetamine addicts stay clean, a study led by University of Virginia School of Medicine researcher Dr. Bankole A. Johnson has ...

Scientists create vaccine against heroin high

July 20, 2011
Researchers at The Scripps Research Institute have developed a highly successful vaccine against a heroin high and have proven its therapeutic potential in animal models.

Methamphetamine use increasing again, researchers find

January 25, 2012
(Medical Xpress) -- Use of methamphetamines is on the rise nationally after a decrease a few years ago, according to university researchers.

Study of 'meth babies' finds behavior problems

March 19, 2012
The first study to look at methamphetamine's potential lasting effects on children whose mothers used it in pregnancy finds these kids at higher risk for behavior problems than other children.

Recommended for you

Stress in pregnancy linked to changes in infant's nervous system, less smiling, less resilience

November 23, 2017
Maternal stress during the second trimester of pregnancy may influence the nervous system of the developing child, both before and after birth, and may have subtle effects on temperament, resulting in less smiling and engagement, ...

Schizophrenia drug development may be 'de-risked' with new research tool

November 22, 2017
Researchers at Columbia University Medical Center (CUMC) and the New York State Psychiatric Institute (NYSPI) have identified biomarkers that can aid in the development of better treatments for schizophrenia.

Study finds infection and schizophrenia symptom link

November 22, 2017
If a mother's immune system is activated by infection during pregnancy, it could result in critical cognitive deficits linked to schizophrenia in her offspring, a University of Otago study has revealed.

Self-harm, suicide attempts climb among US girls, study says

November 21, 2017
Attempted suicides, drug overdoses, cutting and other types of self-injury have increased substantially in U.S. girls, a 15-year study of emergency room visits found.

Car, stroller, juice: Babies understand when words are related

November 20, 2017
The meaning behind infants' screeches, squeals and wails may frustrate and confound sleep-deprived new parents. But at an age when babies cannot yet speak to us in words, they are already avid students of language.

Simple EKG can determine whether patient has depression or bipolar disorder

November 20, 2017
A groundbreaking Loyola Medicine study suggests that a simple 15-minute electrocardiogram could help a physician determine whether a patient has major depression or bipolar disorder.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

NOM
not rated yet Nov 01, 2012
Sneek the vaccine into tobacco products and P would no longer be a problem.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.