NicVax, made by Nabi Biopharmaceuticals (NASDAQ:NABI), was tested on 301 study participants in nine centers across the country, the University of Nebraska Medical Center said Wednesday in a news release.

Dr. Stephen Rennard, who presented the study results at the 80th American Heart Association Scientific Sessions in Orlando, Fla., said there was a significant relationship between anti-nicotine antibody levels and continuous abstinence from smoking. He said NicVAX was well-tolerated and showed no differences in adverse events or in local/systemic reactions between placebo and each active vaccine group.

Researchers said the vaccine works by preventing nicotine from entering the brain, which may reduce the pleasurable effects of smoking.