Nicotine Vaccines Research Articles

A conjugate vaccine using enantiopure hapten imparts superior nicotine-binding capacity.

A leading nicotine conjugate vaccine was only efficacious for one-third of clinical trial participants, likely due in part to its use of racemic nicotine hapten, (±)-3'-AmNic. Immunization of male Wistar rats with (+)-, (-)-, or (±)-3'-AmNicSucTT and subsequent antibody immunoassays suggest that a vaccine using enantiopure (-)-3'-AmNic hapten imparts superior capacity to bind (-)-nicotine. Future nicotine vaccine clinical candidates must incorporate this design consideration (i.e., hapten enantiopurity) in order to maximize efficacy.

Vaccination against smoking: an annotated agenda for debate. A review of scientific journals, 2001–13

The ongoing development of novel nicotine vaccines makes it urgent to identify the normative questions around this innovative health technology against smoking. A qualitative thematic analysis of peer-reviewed papers on nicotine vaccination published between 2001 and 2013. In the scientific discourse, nicotine vaccination is presented in a neurobiological frame as a potent concept for (long-term) smoking cessation. Nicotine vaccination is also considered a hypothetical strategy to prevent nicotine addiction in minors. Ethical assessments are conducted for the use of nicotine vaccination in public health and clinical medicine. Whereas vaccination for primary prevention is usually associated with public health, the hypothetical case of nicotine prevention in minors is also assessed for individualized protection. Therapeutic and preventive applications are given uneven attention: the classic goal of vaccination (primary prevention in minors) receives methodical consideration and invokes lively debate. The unprecedented use of vaccination, namely smoking cessation, is left largely unattended in the ethical analyses. While health innovations such as nicotine vaccination need broad reflection to guide decisions on their further development and possible future implementations, only a small part of the ethical and social issues of this innovative technology has been discussed. For a debate to come into existence, a 'neurobio-psycho-socio-cultural' frame of smoking and quitting appears fruitful. Important topics for reflection are the human activities and social processes in a vaccine-supported quit attempt, next to respect for individuals, possible harms and questions of (global) justice and research ethics.

Efficacy of the nicotine vaccine 3'-AmNic-rEPA (NicVAX) co-administered with varenicline and counselling for smoking cessation: a randomized placebo-controlled trial.

Nicotine vaccination has been proposed as a possible treatment to aid smoking cessation. First efficacy results of the nicotine vaccine 3'-AmNic-rEPA (NicVAX) showed that only a subgroup of the top 30% antibody responders achieved higher abstinence rates than placebo. The present study examined the efficacy of adding NicVAX versus placebo to varenicline and behavioural support as an aid in smoking cessation and relapse prevention. Randomized placebo-controlled trial. Two research centres (Maastricht University Medical Centre and Slotervaart Hospital) in the Netherlands. A total of 558 smokers were assigned randomly to six injections with NicVAX (n = 278) or placebo (n = 280) both co-administered with open label varenicline and behavioural support. Outcomes were prolonged carbon monoxide-validated abstinence from weeks 9 to 52 (primary) and weeks 37 to 52 (secondary). We also performed a pre-planned subgroup analysis in the top 30% antibody responders. There was no difference in abstinence rates between NicVAX and placebo from weeks 9 to 52 [27.7 versus 30.0%, odds ratio (OR) = 0.89, 95% confidence interval (CI) = 0.62-1.29] or weeks 37 to 52 (33.8 versus 33.2%, OR = 1.03, 95% CI = 0.73-1.46). The top 30% antibody responders, compared to the placebo group, showed a non-significant tendency towards higher abstinence rates from weeks 37 to 52 (42.2 versus 33.2%, OR = 1.47, 95% CI = 0.89-2.42). The nicotine vaccine, NicVAX, does not appear to improve the chances of stopping smoking when given in addition to varenicline and behavioural support.

Treatment with a nicotine vaccine does not lead to changes in brain activity during smoking cue exposure or a working memory task.

To assess whether immunization attenuates nicotinic stimulation of the brain and elucidate brain and behavioural responses during exposure to smoking cues and a working memory task. Randomized, placebo-controlled parallel-group, repeated-measures design. Maastricht University, the Netherlands. Forty-eight male smokers were randomized to receive five injections with either 400 μg/ml of the 3'-aminomethylnicotine Pseudomonas aeruginosa r-Exoprotein-conjugated vaccine or placebo. Subjects were tested on two occasions, once after a nicotine challenge and once after a placebo challenge, and were asked to refrain from smoking 10 hours before testing. Reaction-times and accuracies were recorded during an n-back task. Moreover, regional blood oxygenated level-dependent (BOLD) response was measured during this task and during smoking cue exposure. Greater activation was found in response to smoking cues compared to neutral cues in bilateral trans-occipital sulcus (P < 0.005); however, this effect did not survive correction for multiple comparisons. There was no difference in brain activity to smoking cues between the treatment groups and no effects of acute nicotine challenge were established. For the n-back task we found working memory load-sensitive increases in brain activity in several frontal and parietal areas (P < 0.0025). However, no effects of immunization or nicotine challenge were observed. No significant effects of immunization on brain activity in response to a nicotine challenge were established. Therefore this vaccine is not likely to be an effective aid in smoking cessation.

Generation of a universal CD4 memory T cell recall peptide effective in humans, mice and non-human primates

CD4T cells play a key role in humoral immunity by providing help to B cells, enabling effective antibody class switching and affinity maturation. Some vaccines may generate a poor response due to a lack of effective MHC class II epitopes, resulting in ineffective helper T cell activation and recall and consequently poor humoral immunity. It may be beneficial to provide a CD4T cell helper peptide with a vaccine particularly in the case of a poorly immunogenic antigen. Such a T cell helper peptide must be promiscuous in its ability to bind a broad range of MHC class II alleles due to broad allelic variation in the human population. We designed a chimeric MHC class II peptide (TpD) with epitopes from tetanus toxoid and diphtheria toxoid, separated by an internal cathepsin cleavage site. TpD was capable of inducing a memory recall response in peripheral blood mononuclear cells from 20/20 human donors. T cells responding to TpD showed a central memory phenotype. Immunization of mice with a synthetic nicotine nanoparticle vaccine containing TpD showed that the peptide was required for robust antibody production and resulted in a long term CD4 memory T cell recall response.As a pre-clinical model two non-human primate species, rhesus macaques and cynomolgus monkeys, were immunized with a nicotine nanoparticle vaccine and evaluated for an anti-nicotine antibody response and TpD specific memory T cells. We found that 4/4 rhesus monkeys had both sustained antibody production and TpD memory T cells for the duration of the experiment (119 days). In addition 30/30 cynomolgus monkeys dosed with nicotine vaccine nanoparticles showed dose-dependent antibody generation and T cell recall response compared to saline injected controls. In summary we have developed a potent universal memory T cell helper peptide (TpD) that is active in vitro in human PBMCs and in vivo in mice and non-human primates.

Constructing a trial as a personal lifestyle change project: Participants' experiences in a clinical study for nicotine vaccination

The purpose of this study was to gain insight into the experiences and dynamics of the involvement of research participants in a randomized clinical trial for nicotine vaccination. Participants received an experimental nicotine vaccine or a placebo, in addition to quit smoking medication and counseling. The longitudinal design of this qualitative study allowed us to follow people from their first visit to the trial location until the unblinding of their treatment with either verum or placebo vaccine. The empirical data consisted of 49 semi-structured, in-depth interviews, field notes and memos, and trial documents collected in the Netherlands between 2010 and 2012.Participants' expectations and experiences of the innovative nicotine vaccine were characterized by ambivalence: Although they complied with the research design, throughout the study they tinkered with discourses, objects, and activities to make them serve their individual goals. They made the concepts of nicotine vaccination and placebo treatment meaningful for quitting, reshaped the meaning of research tests and obligatory visits to serve their own personal goals, and introduced a new element into the trial by creating space to discuss problems that might endanger the quit attempt. In short, the participants constructed the clinical study for nicotine vaccination as their own personal lifestyle change project.

Immunogenicity of Individual Vaccine Components in a Bivalent Nicotine Vaccine Differ According to Vaccine Formulation and Administration Conditions

Structurally distinct nicotine immunogens can elicit independent antibody responses against nicotine when administered concurrently. Co-administering different nicotine immunogens together as a multivalent vaccine could be a useful way to generate higher antibody levels than with monovalent vaccines alone. The immunogenicity and additivity of monovalent and bivalent nicotine vaccines was studied across a range of immunogen doses, adjuvants, and routes to assess the generality of this approach. Rats were vaccinated with total immunogen doses of 12.5 - 100 μg of 3′-aminomethyl nicotine conjugated to recombinant Pseudomonas exoprotein A (3′-AmNic-rEPA), 6-carboxymethylureido nicotine conjugated to keyhole limpet hemocyanin (6-CMUNic-KLH), or both. Vaccines were administered s.c. in alum or i.p. in Freund’s adjuvant at matched total immunogen doses. When administered s.c. in alum, the contributions of the individual immunogens to total nicotine-specific antibody (NicAb) titers and concentrations were preserved across a range of doses. Antibody affinity for nicotine varied greatly among individuals but was similar for monovalent and bivalent vaccines. However when administered i.p. in Freund’s adjuvant the contributions of the individual immunogens to total NicAb titers and concentrations were compromised at some doses. These results support the possibility of co-administering structurally distinct nicotine immunogens to achieve a more robust immune response than can be obtained with monovalent immunogens alone. Choice of adjuvant was important for the preservation of immunogen component activity.

Increased efficacy of a trivalent nicotine vaccine compared to a dose-matched monovalent vaccine when formulated with alum

Vaccination against nicotine is a potential treatment for tobacco smoking. Clinical trials show effect only in high antibody responders; therefore it is necessary to increase the effectiveness of nicotine vaccines. The use of a multivalent vaccine that activates several B cell populations is a possible approach to increase antibody response. The aim of this study was to investigate whether three different nicotine immunogens could be mixed to generate independent responses resulting in additive antibody titers, and whether this would alter nicotine distribution to a greater extent than antibodies generated by a monovalent vaccine. When immunogens were administered s.c. with alum adjuvant, the trivalent vaccine generated significantly higher titers and prevented the distribution of an i.v. nicotine dose to brain to a greater extent than an equivalent dose of a monovalent vaccine. The number of rats with antibody titers >1:10,000 was significantly increased in the trivalent group compared to the monovalent group. There were no correlations between the titers generated by the different nicotine immunogens in the trivalent vaccine, supporting the hypothesis that the immunogens generated independent responses from distinct populations of B cells. In contrast, when administered i.p. in Freund's adjuvant, the trivalent nicotine vaccine was not more immunogenic than its component monovalent vaccine. Vaccine immunogenicity was suppressed if unconjugated protein was added to the monovalent vaccine formulated in Freund's adjuvant, compared to monovalent vaccine alone. These data suggest a protein–protein interaction that affects titers negatively and is apparent when the vaccines are formulated with Freund's adjuvant. In summary, a trivalent nicotine vaccine formulated with alum showed significantly higher efficacy than a dose-matched monovalent vaccine and may offer a strategy for increasing nicotine vaccine immunogenicity. This approach may be generalizable to other nicotine immunogens or vaccines for other addictive drugs.

A novel and efficient nicotine vaccine using nano-lipoplex as a delivery vehicle

A number of vaccines conjugating nicotine haptens with carrier proteins have been developed to combat nicotine caused tobacco dependence. Some vaccines, such as NicVAX, NicQb, advanced into clinical trials, but none of them were successful. Most of those vaccines have some innate disadvantages such as low nicotine loading capacity, easy degradation, and vulnerable to the clearance by reticulo-endothelial system (RES). Thus, there is undoubtedly an urgent need for developing novel vaccines against nicotine addiction. In this study, we assembled a liposome-protein based nanoparticle as a nicotine hapten delivery system. The nanoparticle (Scheme 1) was constructed by conjugating a model hapten carrier protein, bovine serum albumin (BSA), to cationic liposomes. This nano-sized complex, lipoplex, was characterized using zetasizer, transmission electron microscope (TEM), and flow cytometry. The efficacy of the lipoplex vaccine was evaluated in mice and compared with that of Nicotine-BSA conjugate (Nic-BSA). The lipoplex vaccine with Alum was able to elicit the highest NicAb titer of 11169 ± 2112, which was significantly higher than that induced by either the vaccine without Alum or Nic-BSA with Alum. The significant immunostimulatory effect of this nano-lipoplex may provide a novel strategy to improve the immunogenic ability of current nicotine vaccines or other vaccines using small molecules as immunogens.

Exploring Smokers’ Knowledge and Expectations Toward Nicotine Vaccination: A Qualitative Study

Knowledge and expectations toward smoking cessation therapies may influence effectiveness. Nicotine vaccination is a novel and promising new therapy for smoking cessation. This qualitative study explored smokers’ knowledge and expectations toward nicotine vaccination as well as varenicline and counseling for smoking cessation. We conducted focus group discussions and interviews in 25 smokers at Maastricht University, the Netherlands, in 2010. Data were analyzed using conventional content analysis. Participants had serious misconceptions about the purpose of nicotine vaccination, particularly the belief that nicotine vaccines reduce craving. Expectations toward counseling were highest. These results underline misconceptions smokers can have about cessation therapies.

Pharmacological interventions for smoking cessation: an overview and network meta-analysis.

Pharmacological interventions for smoking cessation: an overview and network meta-analysis.

Preventing Sin: The Ethics of Vaccines Against Smoking

AbstractThe alarming rates of smoking, obesity, and substance abuse pose an enormous challenge for parents and public health officials: how do we prevent children and adolescents from adopting unhealthy behaviors? One new option that may soon be available is the use of nicotine vaccines. Immunological therapies to help smokers stop smoking have shown promise in phase I and II trials; similar therapies could combat smoking addiction before it starts. Nicotine vaccines are distinctive because they confer protection not against infection—the normal target for vaccines—but against enticing pleasures that lead to unhealthy behaviors. As a result, using them preventively in children would be likely to arouse some novel ethical concerns that should be addressed before the vaccines become commonly available and their off‐label use as a preventive measure becomes a real option.In this paper, we consider whether it would be ethical for parents to vaccinate their children against smoking if a nicotine vaccine were to be proven effective as a preventive intervention for children or adolescents. We begin by explaining the current state of nicotine vaccine science and suggesting some likely ethical concerns about allowing parents to have their children receive a vaccine. We then present a preliminary argument for making vaccination permissible, at least if nicotine vaccination substantially reduces the probability that someone subsequently becomes a smoker. We consider a series of possible ethical objections, which are useful for identifying the conditions under which it would be ethical for parents to vaccinate their children against smoking. We conclude that it would be permissible for parents to give their child a nicotine vaccine if the following conditions were met: the vaccine is expected to result in a net benefit to each individual vaccinated, the expected harms from the side effects of the vaccine are lower than the nonvoluntary harms caused by smoking, and there are no other, less manipulative methods available that are as effective at preventing smoking initiation.

Reduced Binding to Nicotinic Receptors After Nicotine Vaccination: Is the Effect Big Enough to Be Clinically Meaningful?

Reduced Binding to Nicotinic Receptors After Nicotine Vaccination: Is the Effect Big Enough to Be Clinically Meaningful?

Effect of a Nicotine Vaccine on Nicotine Binding to β2*-Nicotinic Acetylcholine Receptors In Vivo in Human Tobacco Smokers

Nicotine promotes smoking partly by binding to β2-containing nicotinic acetylcholine receptors (β2*-nAChRs) in the brain. Smoking one tobacco cigarette results in occupation of 80% of β2*-nAChRs for more than 6 hours. This likely contributes to maintenance of smoking dependence and cessation difficulty. Developing nicotine vaccines could improve treatments. The authors used [123I]5-I-A-85380 single photon emission computed tomography (SPECT) to evaluate the effect of 3'-AmNic-rEPA on the amount of nicotine that binds to β2*-nAChRs in smokers' brain cortical and subcortical regions. Eleven smokers who smoked an average of 19 cigarettes per day, had smoked for 10 years on average, and met criteria for nicotine dependence were given SPECT scans on two days: before and after immunization with 4-400 μg of 3'-AmNic-rEPA. On scan days, three 30-minute baseline emission scans were followed by intravenous administration of nicotine (1.5 mg/70 kg body weight) and up to nine 30-minute emission scans. β2*-nAChR availability was quantified as VT/fP (total distribution volume divided by free plasma concentration), and nicotine binding was derived by the Lassen plot approach. Immunization led to a 12.5% reduction in nicotine binding. Nicotine bound to β2*-nAChRs correlated positively with nicotine injected before but not after vaccination. The daily number of cigarettes and desire for a cigarette decreased after vaccination. This proof-of-concept study demonstrates that immunization with nicotine vaccine can reduce the amount of nicotine binding to β2*-nAChRs and disrupt the relationship between administered nicotine and nicotine available to occupy β2*-nAChRs.

Nicotine Vaccine’s Effects on Brain Evaluated

The road toward an effective nicotine vaccine has so far been quite rocky, but researchers foresee eventual success.

Niccine(R), a Nicotine Vaccine, for Relapse Prevention: A Phase II, Randomized, Placebo-Controlled, Multicenter Clinical Trial

A nicotine vaccine could prevent relapse to smoking by hindering blood nicotine from reaching the brain. Niccine® is a nicotine hapten tetanus-toxoid conjugate vaccine. The present study evaluated the clinical efficacy of Niccine for tobacco smoking relapse prevention. Cigarette smokers (n = 355) aged 25-50 years were enrolled in a randomized, double-blind, parallel group 1-year trial encompassing 16 visits and 16 telephone calls. Niccine 40 μg or placebo was administered on Days 0, 28, 56, 90, 150, and 210. Between Days 56-98, subjects were treated with varenicline to aid cessation, targeted for Day 70. Only individuals abstinent between Days 90-98 (n = 265) were allowed to continue to 1 year (n = 219). Relapse to smoking was defined as >5 cigarettes within 7 days or since the last contact, or smoking on >5 occasions within 7 days or since the last contact. At 1 year, nonrelapse was 43.3% in the Niccine versus 51.1% in the placebo groups (difference = -7.9%; 95% CI = -20.6% to 4.9%). There was no benefit of Niccine on smoking status at 6 or 9 months, exhaled carbon monoxide levels, time to relapse, abstinence, withdrawal symptoms, or smoking reinforcement. Nicotine antibody levels increased (mean = 1.34 μg/ml; SD = 2.84 μg/ml) in the Niccine group, but were not related to relapse. Adverse events except hypersensitivity and compensatory smoking did not differ between groups. This nicotine vaccine appeared well tolerated but did not influence trajectories of relapse possibly because of insufficient antibody levels or lack of efficacy of the vaccine concept for relapse prevention.

Nicotine Vaccines for Smoking Cessation

Nicotine Vaccines for Smoking Cessation

Therapeutic vaccines against tobacco addiction

Most smokers are aware of the dangers of smoking and want to quit, yet few are successful owing to the highly addictive properties of nicotine. Available smoking cessation tools include pharmacotherapies that act in the CNS and show modest long-term efficacy. Additionally, there are emerging concerns that they may cause adverse neuropsychiatric events. Antinicotine vaccines have been used experimentally as aids to smoking cessation. It is hypothesized that antibody capture of nicotine in the bloodstream would prevent it from crossing the blood–brain barrier and reaching the nicotinic receptors. The advantage of the approach includes the relatively gradual rise of antibody levels, which may reduce nicotine withdrawal symptoms, and the possible persistence of the antibodies potentially provides long-term protection, possibly preventing relapse. Proof-of-concept studies of at least two vaccine candidates have shown correlations between antinicotine antibody exposure and smoking abstinence. Unfortunately, the only vaccine tested in two large, randomized Phase III trials, 3’-amino-methyl-nicotine r-exoprotein A conjugate vaccine (NicVAX®, Nabi Biopharmaceuticals, MD, USA), did not demonstrate efficacy. However, despite the lack of efficacy, there is good reason for continued optimism. This review will summarize the current status of the development of nicotine vaccines, discuss possible causes for the mixed results and review future scientific directions.

Enhancing Children against Unhealthy Behaviors-An Ethical and Policy Assessment of Using a Nicotine Vaccine.

Health behaviors such as tobacco use contribute significantly to poor health. It is widely recognized that efforts to prevent poor health outcomes should begin in early childhood. Biomedical enhancements, such as a nicotine vaccine, are now emerging and have potential to be used for primary prevention of common diseases. In anticipation of such enhancements, it is important that we begin to consider the ethical and policy appropriateness of their use with children. The main ethical concerns raised by enhancing children relate to their impact on children's well-being and autonomy. These concerns are significant, however they do not appear to apply in the case of the nicotine vaccine; indeed the vaccine could even further these goals for children. Nevertheless, concerns about broadly applying this enhancement may be more challenging. The vaccine may be less cost-effective than alternative public efforts to prevent tobacco use, utilizing it could distract from addressing the foundational causes of smoking and it might not be publically acceptable. Empirical research about these concerns is needed to ascertain their likelihood and impact as well as how they could be minimized. This research could help determine whether behavior-related enhancements hold promise for improving children's health.

Nicotine vaccines for smoking cessation-present and future

Background: Worldwide tobacco is the leading cause of preventable death. Anew treatment in smoking cessation and relapse prevention is nicotine vaccination which is based on active immunization against the nicotine molecule. This article aimed to review the mechanism of action, current status of research and future aspects for the development of vaccines against nicotine. Materials & Method: The literature search of publications indexed was carried out in PubMed, Medline, Google scholar databases. Total 25 animal trials, human trials under various phases of clinical trials, unpublished document and cross-sectional survey were reviewed. Results: This immunization will act on immune system to produce nicotine-specific antibodies that sequester nicotine in the blood stream, after inhaling tobacco products. Nicotine vaccines are irreversible, provide protection over years and need booster injections. Efficiency of the vaccines is directly related to the antibody levels which help to optimize the vaccine effect. Nicotine vaccines are today in an advanced stage of clinical evaluation trials. Conclusions: Though, nicotine vaccine has considerable therapeutic potential, they do not target the non pharmacological factors that maintain tobacco dependence. So combination of nicotine vaccine with behavioral interventions would be effective mode to motivate abstinence from tobacco use.