Alzheimer's Disease: A Brief History of Immunotherapies Targeting Amyloid ß.

Alzheimer's disease (AD) is the most common form of dementia and may contribute to 60-70% of cases. Worldwide, around 50 million people suffer from dementia and the prediction is that the number will more than triple by 2050, as the population ages. Extracellular protein aggregation and plaque deposition as well as accumulation of intracellular neurofibrillary tangles, all leading to neurodegeneration, are the hallmarks of brains with Alzheimer's disease. Therapeutic strategies including active and passive immunizations have been widely explored in the last two decades. Several compounds have shown promising results in many AD animal models. To date, only symptomatic treatments are available and because of the alarming epidemiological data, novel therapeutic strategies to prevent, mitigate, or delay the onset of AD are required. In this mini-review, we focus on our understanding of AD pathobiology and discuss current active and passive immunomodulating therapies targeting amyloid-ß protein.

A scalable and highly immunogenic virus-like particle-based vaccine against SARS-CoV-2.

BACKGROUND: SARS-CoV-2 caused one of the most devastating pandemics in the recent history of mankind. Due to various countermeasures, including lock-downs, wearing masks, and increased hygiene, the virus has been controlled in some parts of the world. More recently, the availability of vaccines, based on RNA or adenoviruses, has greatly added to our ability to keep the virus at bay; again, however, in some parts of the world only. While available vaccines are effective, it would be desirable to also have more classical vaccines at hand for the future. Key feature of vaccines for long-term control of SARS-CoV-2 would be inexpensive production at large scale, ability to make multiple booster injections, and long-term stability at 4℃. METHODS: Here, we describe such a vaccine candidate, consisting of the SARS-CoV-2 receptor-binding motif (RBM) grafted genetically onto the surface of the immunologically optimized cucumber mosaic virus, called CuMVTT -RBM. RESULTS: Using bacterial fermentation and continuous flow centrifugation for purification, the yield of the production process is estimated to be >2.5 million doses per 1000-litre fermenter run. We demonstrate that the candidate vaccine is highly immunogenic in mice and rabbits and induces more high avidity antibodies compared to convalescent human sera. The induced antibodies are more cross-reactive to mutant RBDs of variants of concern (VoC). Furthermore, antibody responses are neutralizing and long-lived. In addition, the vaccine candidate was stable for at least 14 months at 4℃. CONCLUSION: Thus, the here presented VLP-based vaccine may be a good candidate for use as conventional vaccine in the long term.

Immunization of cats to induce neutralizing antibodies against Fel d 1, the major feline allergen in human subjects.

BACKGROUND: Cat allergy in human subjects is usually caused by the major cat allergen Fel d 1 and is found in approximately 10% of the Western population. Currently, there is no efficient and safe therapy for cat allergy available. Allergic patients usually try to avoid cats or treat their allergy symptoms. OBJECTIVE: We developed a new strategy to treat Fel d 1-induced allergy in human subjects by immunizing cats against their own major allergen, Fel d 1. METHODS: A conjugate vaccine consisting of recombinant Fel d 1 and a virus-like particle derived from the cucumber mosaic virus containing the tetanus toxin-derived universal T-cell epitope tt830-843 (CuMVTT) was used to immunize cats. A first tolerability and immunogenicity study, including a boost injection, was conducted by using the Fel-CuMVTT vaccine alone or in combination with an adjuvant. RESULTS: The vaccine was well tolerated and had no overt toxic effect. All cats induced a strong and sustained specific IgG antibody response. The induced anti-Fel d 1 antibodies were of high affinity and exhibited a strong neutralization ability tested both in vitro and in vivo. A reduction in the endogenous allergen level and a reduced allergenicity of tear samples, were observed. CONCLUSION: Vaccination of cats with Fel-CuMVTT induces neutralizing antibodies and might result in reduced symptoms of allergic cat owners. Both human subjects and animals could profit from this treatment because allergic cat owners would reduce their risk of developing chronic diseases, such as asthma, and become more tolerant of their cats, which therefore could stay in the households and not need to be relinquished to animal shelters.

Development of an Interleukin-1ß Vaccine in Patients with Type 2 Diabetes.

Interleukin-1ß (IL-1ß) is a key cytokine involved in inflammatory illnesses including rare hereditary diseases and common chronic inflammatory conditions as gout, rheumatoid arthritis, and type 2 diabetes mellitus, suggesting reduction of IL-1ß activity as new treatment strategy. The objective of our study was to assess safety, antibody response, and preliminary efficacy of a novel vaccine against IL-1ß. The vaccine hIL1bQb consisting of full-length, recombinant IL-1ß coupled to virus-like particles was tested in a preclinical and clinical, randomized, placebo-controlled, double-blind study in patients with type 2 diabetes. The preclinical simian study showed prompt induction of IL-1ß-specific antibodies upon vaccination, while neutralizing antibodies appeared with delay. In the clinical study with 48 type 2 diabetic patients, neutralizing IL-1ß-specific antibody responses were detectable after six injections with doses of 900 µg. The development of neutralizing antibodies was associated with higher number of study drug injections, lower baseline body mass index, improvement of glycemia, and C-reactive protein (CRP). The vaccine hIL1bQb was safe and well-tolerated with no differences regarding adverse events between patients receiving hIL1bQb compared to placebo. This is the first description of a vaccine against IL-1ß and represents a new treatment option for IL-1ß-dependent diseases such as type 2 diabetes mellitus (ClinicalTrials.gov NCT00924105).

A VLP-based vaccine against interleukin-1α protects mice from atherosclerosis.

Interleukin (IL)-1α is a potent proinflammatory cytokine that has been implicated in the development of atherosclerosis. We investigated whether a vaccine inducing IL-1α neutralizing antibodies could interfere with disease progression in a murine model of atherosclerosis. We immunized Apolipoprothin E (ApoE)-deficient mice with a vaccine (IL-1α-C-Qß) consisting of full-length, native IL-1α chemically conjugated to virus-like particles derived from the bacteriophage Qß. ApoE(-/-) mice were administered six injections of IL-1α-C-Qß or nonconjugated Qß over a period of 160 days while being maintained on a western diet. Atherosclerosis was measured in the descending aorta and in cross-sections at the aortic root. Macrophage infiltration in the aorta was measured using CD68. Expression levels of VCAM-1, ICAM-1, and MCP-1 were quantified by RT-PCR. Immunization against IL-1α reduced plaque progression in the descending aorta by 50% and at the aortic root by 37%. Macrophage infiltration in the aorta was reduced by 22%. Inflammation was also reduced in the adventitia, with a decrease of 54% in peri-aortic infiltrate score and reduced expression levels of VCAM-1 and ICAM-1. Active immunization targeting IL-1α reduced both the inflammatory reaction in the plaque as well as plaque progression. In summary, vaccination against IL-1α protected ApoE(-/-) mice against disease, suggesting that this may be a potential treatment option for atherosclerosis.

A virus-like particle-based anti-nerve growth factor vaccine reduces inflammatory hyperalgesia: potential long-term therapy for chronic pain.

Chronic pain resulting from inflammatory and neuropathic disorders causes considerable economic and social burden. For a substantial proportion of patients, conventional drug treatments do not provide adequate pain relief. Consequently, novel approaches to pain management, involving alternative targets and new therapeutic modalities compatible with chronic use, are being sought. Nerve growth factor (NGF) is a major mediator of chronic pain. Clinical testing of NGF antagonists is ongoing, and clinical proof of concept has been established with a neutralizing mAb. Active immunization, with the goal of inducing therapeutically effective neutralizing autoreactive Abs, is recognized as a potential treatment option for chronic diseases. We have sought to determine if such a strategy could be applied to chronic pain by targeting NGF with a virus-like particle (VLP)-based vaccine. A vaccine comprising recombinant murine NGF conjugated to VLPs from the bacteriophage Qß (NGFQß) was produced. Immunization of mice with NGFQß induced anti-NGF-specific IgG Abs capable of neutralizing NGF. Titers could be sustained over 1 y by periodic immunization but declined in the absence of boosting. Vaccination with NGFQß substantially reduced hyperalgesia in collagen-induced arthritis or postinjection of zymosan A, two models of inflammatory pain. Long-term NGFQß immunization did not change sensory or sympathetic innervation patterns or induce cholinergic deficits in the forebrain, nor did it interfere with blood-brain barrier integrity. Thus, autovaccination targeting NGF using a VLP-based approach may represent a novel modality for the treatment of chronic pain.

The second-generation active Aß immunotherapy CAD106 reduces amyloid accumulation in APP transgenic mice while minimizing potential side effects.

Immunization against amyloid-ß (Aß) can reduce amyloid accumulation in vivo and is considered a potential therapeutic approach for Alzheimer's disease. However, it has been associated with meningoencephalitis thought to be mediated by inflammatory T-cells. With the aim of producing an immunogenic vaccine without this side effect, we designed CAD106 comprising Aß1-6 coupled to the virus-like particle Qß. Immunization with this vaccine did not activate Aß-specific T-cells. In APP transgenic mice, CAD106 induced efficacious Aß antibody titers of different IgG subclasses mainly recognizing the Aß3-6 epitope. CAD106 reduced brain amyloid accumulation in two APP transgenic mouse lines. Plaque number was a more sensitive readout than plaque area, followed by Aß42 and Aß40 levels. Studies with very strong overall amyloid reduction showed an increase in vascular Aß, which atypically was nonfibrillar. The efficacy of Aß immunotherapy depended on the Aß levels and thus differed between animal models, brain regions, and stage of amyloid deposition. Therefore, animal studies may not quantitatively predict the effect in human Alzheimer's disease. Our studies provided no evidence for increased microhemorrhages or inflammatory reactions in amyloid-containing brain. In rhesus monkeys, CAD106 induced a similar antibody response as in mice. The antibodies stained amyloid deposits on tissue sections of mouse and human brain but did not label cellular structures containing APP. They reacted with Aß monomers and oligomers and blocked Aß toxicity in cell culture. We conclude that CAD106 immunization is suited to interfere with Aß aggregation and its downstream detrimental effects.

A VLP-based vaccine targeting domain III of the West Nile virus E protein protects from lethal infection in mice.

BACKGROUND: Since its first appearance in the USA in 1999, West Nile virus (WNV) has spread in the Western hemisphere and continues to represent an important public health concern. In the absence of effective treatment, there is a medical need for the development of a safe and efficient vaccine. Live attenuated WNV vaccines have shown promise in preclinical and clinical studies but might carry inherent risks due to the possibility of reversion to more virulent forms. Subunit vaccines based on the large envelope (E) glycoprotein of WNV have therefore been explored as an alternative approach. Although these vaccines were shown to protect from disease in animal models, multiple injections and/or strong adjuvants were required to reach efficacy, underscoring the need for more immunogenic, yet safe DIII-based vaccines. RESULTS: We produced a conjugate vaccine against WNV consisting of recombinantly expressed domain III (DIII) of the E glycoprotein chemically cross-linked to virus-like particles derived from the recently discovered bacteriophage AP205. In contrast to isolated DIII protein, which required three administrations to induce detectable antibody titers in mice, high titers of DIII-specific antibodies were induced after a single injection of the conjugate vaccine. These antibodies were able to neutralize the virus in vitro and provided partial protection from a challenge with a lethal dose of WNV. Three injections of the vaccine induced high titers of virus-neutralizing antibodies, and completely protected mice from WNV infection. CONCLUSIONS: The immunogenicity of DIII can be strongly enhanced by conjugation to virus-like particles of the bacteriophage AP205. The superior immunogenicity of the conjugate vaccine with respect to other DIII-based subunit vaccines, its anticipated favourable safety profile and low production costs highlight its potential as an efficacious and cost-effective prophylaxis against WNV.

Immunization of Cats against Fel d 1 Results in Reduced Allergic Symptoms of Owners.

An innovative approach was tested to treat cat allergy in humans by vaccinating cats with Fel-CuMV (HypoCatTM), a vaccine against the major cat allergen Fel d 1 based on virus-like particles derived from cucumber mosaic virus (CuMV-VLPs). Upon vaccination, cats develop neutralizing antibodies against the allergen Fel d 1, which reduces the level of reactive allergen, thus lowering the symptoms or even preventing allergic reactions in humans. The combined methodological field study included ten cat-allergic participants who lived together with their cats (n = 13), that were immunized with Fel-CuMV. The aim was to determine methods for measuring a change in allergic symptoms. A home-based provocation test (petting time and organ specific symptom score (OSSS)) and a general weekly (or monthly) symptom score (G(W)SS) were used to assess changes in allergic symptoms. The petting time until a pre-defined level of allergic symptoms was reached increased already early after vaccination of the cats and was apparent over the course of the study. In addition, the OSSS after provocation and G(W)SS recorded a persistent reduction in symptoms over the study period and could serve for long-term assessment. Hence, the immunization of cats with HypoCatTM (Fel-CuMV) may have a positive impact on the cat allergy of the owner, and changes could be assessed by the provocation test as well as G(W)SS.

Effect of immunisation against angiotensin II with CYT006-AngQb on ambulatory blood pressure: a double-blind, randomised, placebo-controlled phase IIa study.

BACKGROUND: Hypertension can be controlled adequately with existing drugs such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Nevertheless, treatment success is often restricted by patients not adhering to treatment. Immunisation against angiotensin II could solve this problem. We investigated the safety and efficacy of CYT006-AngQb-a vaccine based on a virus-like particle-that targets angiotensin II to reduce ambulatory blood pressure. METHODS: In this multicentre, double-blind, randomised, placebo-controlled phase IIa trial, 72 patients with mild-to-moderate hypertension were randomly assigned with a computer-generated randomisation list to receive subcutaneous injections of either 100 mug CYT006-AngQb (n=24), 300 mug CYT006-AngQb (24), or placebo (24), at weeks 0, 4, and 12. 24-h ambulatory blood pressure was measured before treatment and at week 14. The primary outcomes were safety and tolerability. Analyses were done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00500786. FINDINGS: Two patients in the 100 mug group, three in the 300 mug group, and none in the placebo group discontinued study treatment. All patients were included in safety analyses; efficacy analyses did not include the five dropouts, for whom no data were available at week 14. Five serious adverse events were reported (two in the 100 mug group, two in the 300 mug group, and one in the placebo group); none were deemed to be treatment related. Most side-effects were mild, transient reactions at the injection site. Mild, transient influenza-like symptoms were seen in three patients in the 100 mug group, seven in the 300 mug group, and none in the placebo group. In the 300 mug group, there was a reduction from baseline in mean ambulatory daytime blood pressure at week 14 by -9.0/-4.0 mm Hg compared with placebo (p=0.015 for systolic and 0.064 for diastolic). The 300 mug dose reduced the early morning blood-pressure surge compared with placebo (change at 0800 h -25/-13 mm Hg; p<0.0001 for systolic, p=0.0035 for diastolic). INTERPRETATION: Immunisation with CYT006-AngQb was associated with no serious adverse events; most observed adverse events were consistent with local or systemic responses similar to those seen with other vaccines. The 300 mug dose reduced blood pressure in patients with mild-to-moderate hypertension during the daytime, especially in the early morning. FUNDING: Cytos Biotechnology AG.

A vaccine against Alzheimer`s disease: anything left but faith?

INTRODUCTION: Alzheimer's disease looms as a profound and growing threat to future human health. The disease is thought to be primarily driven by aberrant proteolysis of the amyloid precursor protein (APP) and amyloid beta (Aß) plaque deposition. AREAS COVERED: We provide an overview of the molecular pathology that leads to an increase in Aß peptide accumulation, of the mechanism of action for antibody mediated therapies and of the therapeutic vaccines that target Aß under development. We also discuss the rationale for using vaccines in the early stages of the disease. EXPERT OPINION: The major components of ß-amyloid plaques are Aß1-42 and Aß1-40 peptides derived from the APP. Reducing these plaques by means of passive or active vaccination against Aß-peptides has been a long-running endeavor but with disappointing results as the impact on disease progression has been minimal. The data gathered to date could suggest that antibodies do not work, mainly because the studies have not been performed in an optimal fashion. The emerging views are that patients should be treated earlier, ideally in the prodromal or symptom free stage, antibody levels have to be high and the correct epitope must be targeted. More clinical trials to fully explore the potential of vaccines are therefore warranted.

Designing recombinant vaccines with viral properties: a rational approach to more effective vaccines.

One of the great demands and challenges for vaccination is to successfully target the pathogens responsible for much of mankind's chronic disease burden including: AIDS, infectious hepatitis, tuberculosis and malaria. Another is realizing the potential of therapeutic immunization to cure diseases such as cancer, allergy and inflammatory autoimmunity. To achieve these objectives, the fundamental insights gained from immunology, genomics, molecular-cellular biology and vaccinology must be implemented in order to develop more effective, better defined and safer vaccines. As an illustrative example of this we examine the key features of viruses that are known to be responsible for eliciting superb host immune responses. These insights have formed a basis for understanding the effectiveness of existing vaccines and provide a framework for designing and developing new vaccines better able to meet pressing unmet medical needs. The key immunogenic properties of viruses that are understood to date and are currently being applied include: their particulate nature, their highly repetitive and ordered structures, their ability to induce innate immunity with consequent conditioning of adaptive responses and the kinetics and distribution of viral antigens during infection. Vaccines and vaccine-formulations recently registered for use in humans already incorporate some of these elements. Of great anticipation is the progress of the next-generation vaccines now advancing through the various stages of research and development. Vaccines which, by way of rational design, incorporate viral properties to induce tailored responses and thus have the potential to provide safer and more effective prophylaxis and therapies.

A vaccine for hypertension based on virus-like particles: preclinical efficacy and phase I safety and immunogenicity.

BACKGROUND: Despite the availability of efficacious drugs, the success of treating hypertension is limited by patients' inconsistent drug intake. Immunization against angiotensin II may offer a valuable alternative to conventional drugs for the treatment of hypertension, because vaccines induce relatively long-lasting effects and do not require daily dosing. Here we describe the preclinical development and the phase I clinical trial testing of a virus-like particle (VLP)-based antihypertensive vaccine. METHODS AND RESULTS: An angiotensin II-derived peptide was conjugated to the VLP Qbeta (AngQb). AngQb was highly immunogenic in mice and rats. To test for efficacy, spontaneously hypertensive rats (SHR) were immunized with 400 microg AngQb or VLP alone. Group mean systolic blood pressure (SBP) was reduced by up to 21 mmHg (159 +/- 2 versus 180 +/- 5 mmHg, P < 0.001), and total angiotensin II levels (antibody-bound and free) were increased ninefold (85 +/- 20 versus 9 +/- 1 pmol/l, P = 0.002) compared with VLP controls. SHR treated with the angiotensin-converting enzyme (ACE) inhibitor ramipril (1 mg/kg per day by mouth) reached an SBP of 155 +/- 2 mmHg. Twelve healthy volunteers of a placebo-controlled randomized phase I trial were injected once with 100 microg AngQb. Angiotensin II-specific antibodies were raised in all subjects (100% responder rate) and AngQb was well tolerated. CONCLUSIONS: AngQb reduces blood pressure in SHR to levels obtained with an ACE inhibitor, and is immunogenic and well tolerated in humans. Therefore, vaccination against angiotensin II has the potential to become a useful antihypertensive treatment providing long-lasting effects and improving patient compliance.

Incorporation of tetanus-epitope into virus-like particles achieves vaccine responses even in older recipients in models of psoriasis, Alzheimer's and cat allergy.

Monoclonal antibodies are widely used to treat non-infectious conditions but are costly. Vaccines could offer a cost-effective alternative but have been limited by sub-optimal T-cell stimulation and/or weak vaccine responses in recipients, for example, in elderly patients. We have previously shown that the repetitive structure of virus-like-particles (VLPs) can effectively bypass self-tolerance in therapeutic vaccines. Their efficacy could be increased even further by the incorporation of an epitope stimulating T cell help. However, the self-assembly and stability of VLPs from envelope monomer proteins is sensitive to geometry, rendering the incorporation of foreign epitopes difficult. We here show that it is possible to engineer VLPs derived from a non human-pathogenic plant virus to incorporate a powerful T-cell-stimulatory epitope derived from Tetanus toxoid. These VLPs (termed CMVTT) retain self-assembly as well as long-term stability. Since Th cell memory to Tetanus is near universal in humans, CMVTT-based vaccines can deliver robust antibody-responses even under limiting conditions. By way of proof of concept, we tested a range of such vaccines against chronic inflammatory conditions (model: psoriasis, antigen: interleukin-17), neurodegenerative (Alzheimer's, ß-amyloid), and allergic disease (cat allergy, Fel-d1), respectively. Vaccine responses were uniformly strong, selective, efficient in vivo, observed even in old mice, and employing low vaccine doses. In addition, randomly ascertained human blood cells were reactive to CMVTT-VLPs, confirming recognition of the incorporated Tetanus epitope. The CMVTT-VLP platform is adaptable to almost any antigen and its features and performance are ideally suited for the design of vaccines delivering enhanced responsiveness in aging populations.

Preclinical efficacy and safety of an anti-IL-1ß vaccine for the treatment of type 2 diabetes.

Neutralization of the inflammatory cytokine interleukin-1ß (IL-1ß) is a promising new strategy to prevent the ß-cell destruction, which leads to type 2 diabetes. Here, we describe the preclinical development of a therapeutic vaccine against IL-1ß consisting of a detoxified version of IL-1ß chemically cross-linked to virus-like particles of the bacteriophage Qß. The vaccine was well tolerated and induced robust antibody responses in mice, which neutralized the biological activity of IL-1ß, as shown both in cellular assays and in challenge experiments in vivo. Antibody titers were long lasting but reversible over time and not associated with the development of potentially harmful T cell responses against IL-1ß. Neutralization of IL-1ß by vaccine-induced antibodies had no influence on the immune responses of mice to Listeria monocytogenes and Mycobacterium tuberculosis. In a diet-induced model of type 2 diabetes, immunized mice showed improved glucose tolerance, which was mediated by improved insulin secretion by pancreatic ß-cells. Hence, immunization with IL-1ß conjugated to virus-like particles has the potential to become a safe, efficacious, and cost-effective therapy for the prevention and long-term treatment of type 2 diabetes.

Bacterially produced recombinant influenza vaccines based on virus-like particles.

Although current influenza vaccines are effective in general, there is an urgent need for the development of new technologies to improve vaccine production timelines, capacities and immunogenicity. Herein, we describe the development of an influenza vaccine technology which enables recombinant production of highly efficient influenza vaccines in bacterial expression systems. The globular head domain of influenza hemagglutinin, comprising most of the protein's neutralizing epitopes, was expressed in E. coli and covalently conjugated to bacteriophage-derived virus-like particles produced independently in E.coli. Conjugate influenza vaccines produced this way were used to immunize mice and found to elicit immune sera with high antibody titers specific for the native influenza hemagglutinin protein and high hemagglutination-inhibition titers. Moreover vaccination with these vaccines induced full protection against lethal challenges with homologous and highly drifted influenza strains.

Therapeutic vaccines for chronic diseases: successes and technical challenges.

Chronic, non-communicable diseases are the major cause of death and disability worldwide and have replaced infectious diseases as the major burden of society in large parts of the world. Despite the complexity of chronic diseases, relatively few predisposing risk factors have been identified by the World Health Organization. Those include smoking, alcohol abuse, obesity, high cholesterol and high blood pressure as the cause of many of these chronic conditions. Here, we discuss several examples of vaccines that target these risk factors with the aim of preventing the associated diseases and some of the challenges they face.

Vaccine delivery: a matter of size, geometry, kinetics and molecular patterns.

Researchers working on the development of vaccines face an inherent dilemma: to maximize immunogenicity without compromising safety and tolerability. Early vaccines often induced long-lived protective immune responses, but tolerability was a major problem. Newer vaccines have very few side effects but can be of limited immunogenicity. One way to tackle this problem is to design vaccines that have all the properties of pathogens with the exception of causing disease. Key features of pathogens that can be mimicked by vaccine delivery systems are their size, shape and surface molecule organization. In addition, pathogen-associated molecular patterns can be used to induce innate immune responses that promote adaptive immunity. In this Review, we discuss the approaches currently being used to optimize the delivery of antigens and enhance vaccine efficacy.

Combined vaccination against IL-5 and eotaxin blocks eosinophilia in mice.

Interleukin-5 (IL-5) is a cytokine which is essential for the maturation of eosinophils in bone marrow and for their release into the blood. Eotaxin is a CC type chemokine implicated in the recruitment of eosinophils in a variety of inflammatory disorders. Since eosinophil-activity is governed by these two pathways, we targeted both IL-5 and eotaxin by active vaccination to block eosinophilia. We produced two vaccines by chemically cross-linking IL-5 or eotaxin to a virus-like particle (VLP) derived from the bacteriophage Qbeta, yielding highly repetitive arrays of these cytokines on the VLP surface. Both vaccines overcame self-tolerance and induced high antibody titers against the corresponding self-molecules in mice. Immunization with either of the two vaccines reduced eosinophilic inflammation of the lung in an ovalbumin (OVA) based mouse model of allergic airway inflammation. Animals immunized with the two vaccines at the same time developed high antibody titers against both cytokines and also reduced eosinophil-infiltration of the lung. These data demonstrate that targeting either IL-5 or eotaxin may lower eosinophilia. Simultaneous immunization against IL-5 and eotaxin demonstrates that such a therapeutic approach may be used to treat complex disorders in which multiple mediators are involved.