9and10, the level of sensitivity analysis results showed that resting cotinine levels and smoking status have a detrimental effect on nicotine vaccine overall performance, especially when the elicited antibodies have a high affinity for cotinine. and fed into the human being PBPK model. Model predictions suggested that all three parameters, in addition to smoking status, have a sizable impact on anti-nicotine antibodies ability to prevent nicotine PU 02 from entering the brain and that the antibodies elicited by current human being vaccines do not have adequate binding characteristics to reduce mind nicotine concentrations. If the antibody binding characteristics accomplished in animal studies can similarly be achieved in human being studies, however, nicotine vaccine effectiveness in terms of brain nicotine concentration reduction is expected to meet threshold ideals for alleviating nicotine dependence. Keywords and phrases:Physiologically centered pharmacokinetic model, PBPK, Smoking vaccine, Anti-nicotine antibodies, Smoking disposition, Smoking dependence == 1. Background == The use of tobacco products is the leading PU 02 preventable cause of death in the world today, resulting in nearly six million deaths annually and assisting in the manifestation of many other diseases (World Health Business, 2013). In addition, the economic damages caused by tobacco smoking in the US alone over the past four decades could surpass $7 trillion USD (extrapolated from CDC reported data, unpublished). Existing PU 02 restorative treatments have proven to be more and more ineffective at assisting those with the desire to quit (Messer et al., 2008) and, if current styles continue, more than 1 billion people may die from smoking related diseases in the 21st century (World Health Organization, 2013). Nicotine is the main addictive compound found in tobacco products (Benowitz, 2009). It has been shown to induce rewarding behavior through stimulation of brain mesolimbic dopamine neurons (Corrigall et al., 1992), prompting dependency and directly instigating the withdrawal symptoms experienced by those trying to quit (de Villiers et al., 2010). Intuitively, the addictive properties of tobacco could be avoided if nicotine molecules were prevented from entering the brain. The resulting effect could be a significant reduction in the number of potential quitters that eventually relapse. One possible therapeutic option that applies this concept as a mode of stemming nicotine dependency is the nicotine vaccine. There are currently a number of studies claiming the successful application of a conjugate nicotine vaccine in animals (Hieda et al., 1997,1999,2000;Keyler et al., 1999,2008;Pentel et al., 2000;Pentel and Malin, 2002;Satoskar et al., 2003;de Villiers et al., 2010,2013;Moreno et al., 2010;Cornish et al., 2011;Pravetoni et al., 2011,2012;Lockner et al., 2013,2015;Pryde et al., 2013;Hu et al., 2014;Miller et al., 2014;Zheng et al., 2015). In the majority of these studies, immunogenic carrier proteins are conjugated to nicotine moleculesviaa linker modification added to nicotines pyrrolidine ring or pyrodine ring (Keyler et al., 1999). These newly formed protein-hapten conjugates are then injected into patients with an accompanying adjuvant, eliciting an immune response and prompting the generation of antibodies with a high affinity for nicotine (Raupach et al., 2012). After successful vaccination, exposure to tobacco products (either firsthand or secondhand) results in nicotine being sequestered in the blood and extracellular fluid by the anti-nicotine antibodies (Pentel and Malin, 2002). It is important to note that these antibodies do not MAM3 eliminate nicotine from the body, but rather only temporarily impede the mobility and pharmacokinetic activity of nicotine molecules by forming nicotine-antibody complexes (Hieda et al., 1997). Ultimately, the formation of these nicotine-antibody complexes induces a dampening effect that reduces spikes of nicotine concentration in the brain and provides PU 02 a controlled, incremental release of nicotine in the blood (Keyler et al., 1999). Dampening nicotine kinetics in this way has been proven to aid the dissolution of nicotine dependency in humans who achieve high immunogenic responses to conjugate nicotine vaccines (Hatsukami et al., 2005,2011;Cornuz et al., 2008). Appreciable anti-nicotine antibody concentrations have been achieved in human subjects using protein-hapten conjugate vaccines in the past, with some studies even proving successful enough to proceed to clinical trials (Hatsukami et al., 2005,2011;Maurer et al., 2005;Cornuz et al., 2008;Wagena PU 02 et al., 2008;Esterlis et al., 2013). However, none of these studies have proceeded past Phase III clinical trials due to vaccinated subjects failure to exhibit increased abstinence rates when compared to subjects given a placebo (Raupach et al., 2012). The overall lack of positive results from human studies illuminates a need for new approaches to the nicotine vaccine design process. Therefore, the majority of current nicotine vaccine research focuses on the investigation of the key variables thought to have the most impact on the dampening effect described earlier, such as vaccine immunogenicity and vaccine-elicited antibodies affinity for nicotine and its major metabolites (Raupach et al., 2012). A review of factors that are suspected to have a significant impact on nicotine vaccine efficacy prior to additional animal and human experimentation could aid in.