NicVAX, a nicotine vaccine (3'AmNic-rEPA), has been clinically evaluated to 
determine whether higher antibody (Ab) concentrations are associated with higher 
smoking abstinence rates and whether dosages and frequency of administration are 
associated with increased Ab response. This randomized, double-blinded, 
placebo-controlled multicenter clinical trial (N = 301 smokers) tested the 
results of 200- and 400-µg doses administered four or five times over a period 
of 6 months, as compared with placebo. 3'AmNic-rEPA recipients with the highest 
serum antinicotine Ab response (top 30% by area under the curve (AUC)) were 
significantly more likely than the placebo recipients (24.6% vs. 12.0%, P = 
0.024, odds ratio (OR) = 2.69, 95% confidence interval (CI), 1.14-6.37) to 
attain 8 weeks of continuous abstinence from weeks 19 through 26. The 
five-injection, 400-µg dose regimen elicited the greatest Ab response and 
resulted in significantly higher abstinence rates than placebo. This study 
demonstrates, as proof of concept, that 3'AmNic-rEPA elicits Abs to nicotine and 
is associated with higher continuous abstinence rates (CAR). Its further 
development as a treatment for nicotine dependence is therefore justified.