Assessment Of Alpha-galactosylceramide As A Novel Adjuvant For Pandemic Influenza: A Virua Vaccine
Funder
National Health and Medical Research Council
Funding Amount
$220,042.00
Summary
The occurrence of human infections with pathogenic avian H5N1 Influenza A viruses was the first documentation of these viruses demonstrating an ability to directly transmit from birds to humans. The virulent nature of these infections, and the fact that there is no pre-existing immunity to these viruses in the human population has raised the concern that these viruses may emerge to cause the next influenza pandemic. Vaccination is our most effective way of protecting against influenza infection, ....The occurrence of human infections with pathogenic avian H5N1 Influenza A viruses was the first documentation of these viruses demonstrating an ability to directly transmit from birds to humans. The virulent nature of these infections, and the fact that there is no pre-existing immunity to these viruses in the human population has raised the concern that these viruses may emerge to cause the next influenza pandemic. Vaccination is our most effective way of protecting against influenza infection, however there are no commercially available avian influenza vaccines available. Moreover, recent evidence suggests current vaccines strategies may be less than effective. This proposal aims to evaluate the efficacy of a novel vaccine strategy that promotes immune protection against a potential pandemic influenza strain.Read moreRead less
Immunodominance In Vaccinia Virus And Recombinant Vaccinia Vaccines
Funder
National Health and Medical Research Council
Funding Amount
$388,455.00
Summary
When confronted with an invading microbe, the human immune system does not recognise its overall shape. Instead, the microbe is chopped up into tiny fragments, called peptides, and these can be recognised by special cells of the immune system called T cells which orchestrate a response. We have a good understanding of this chopping process and can predict many of these peptides, but this is only part of the story. Not all peptides will be recognized by a T cell. Further, through processes we do ....When confronted with an invading microbe, the human immune system does not recognise its overall shape. Instead, the microbe is chopped up into tiny fragments, called peptides, and these can be recognised by special cells of the immune system called T cells which orchestrate a response. We have a good understanding of this chopping process and can predict many of these peptides, but this is only part of the story. Not all peptides will be recognized by a T cell. Further, through processes we do not understand well, T cells that recognize only a few out of the many peptides will dominate an entire immune response. As a result, immune responses are focused in such a way that they recognize only a tiny portion of an invading microbe. Focusing of immune responses also occurs during immunization with vaccines. Some new, genetically engineered vaccines use a harmless microbe to carry small parts of more dangerous pathogens. The parts chosen will not cause any disease by themselves, so the whole vaccine is safe. Vaccines built in this way are in clinical trials for diseases such as AIDS and malaria, but do not work as well as was hoped. These new vaccines are largely made up of the carrier and the parts of the microbe we wish to immunize against (e.g. a part of the AIDS virus) will be only a small fraction of the whole vaccine. Ideally we would like the immune system to focus on this small part of our choosing, but the few studies done suggest that this is not the case. In this project we will study vaccines that use a carrier called vaccinia virus. We will test to what extent immune responses are focused inappropriately. We will then genetically alter the virus and use new immunisation strategies to try and shift the focus of the immune response so that it targets the right parts of the vaccine. The ultimate aim is to improve vaccines, but in the process we may learn more about how the immune system chooses its targets.Read moreRead less
The Use Of Inulin-based Adjuvants To Enhance The Effectiveness And Population Coverage Of Influenza Vaccination
Funder
National Health and Medical Research Council
Funding Amount
$250,393.00
Summary
A major obstacle in the development of effective vaccines to protect against bird flu (avian influenza) is the difficulty in producing enough vaccine in a short enough time to be able to protect the population should bird flu become a problem in the human population. Our research is focused on a technique to make vaccines much more effective and thereby reduce the amount of vaccine needed for each person. This would allow many more people to be protected with the same amount of vaccine. This tec ....A major obstacle in the development of effective vaccines to protect against bird flu (avian influenza) is the difficulty in producing enough vaccine in a short enough time to be able to protect the population should bird flu become a problem in the human population. Our research is focused on a technique to make vaccines much more effective and thereby reduce the amount of vaccine needed for each person. This would allow many more people to be protected with the same amount of vaccine. This technology is known as a vaccine adjuvant and we have developed a unique adjuvant based on a natural plant sugar called inulin that has the potential to dramatically enhance existing and new flu vaccines.Read moreRead less
Human cytomegalovirus (HCMV) is a classic example of a group of herpes viruses, which is found universally throughout all geographic locations and socioeconomic groups, and infects 50% of adults in developed countries. HCMV infection is important to certain high-risk groups. Major areas of concern are: (1) the risk of infection to unborn baby during pregnancy, (2) the risk of infection to people who work with children, and (3) the risk of infection to immunocompromised persons (e.g. organ transp ....Human cytomegalovirus (HCMV) is a classic example of a group of herpes viruses, which is found universally throughout all geographic locations and socioeconomic groups, and infects 50% of adults in developed countries. HCMV infection is important to certain high-risk groups. Major areas of concern are: (1) the risk of infection to unborn baby during pregnancy, (2) the risk of infection to people who work with children, and (3) the risk of infection to immunocompromised persons (e.g. organ transplant patients and HIV-infected individuals). Epidemiological studies have shown that 80%-90% of developing unborn babies who acquire congenital HCMV infection displays a variable pattern of pathological sequelae within the first few years of life that may include hearing loss, vision impairment and mental retardation. There is an increasing argument that a reduction in HCMV load will have a significant effect on the sequelae associated with congenital HCMV infection. Indeed, vaccination provides the most practical modality of achieving such a reduction in HCMV load. To develop such a vaccine, formulation based on viral antigens that activate both protective cellular and humoral responses needs to be tested to assess its immunogenicity. No such vaccine is presently available for HCMV. In this application we have sought to develop a prophylactic vaccine and to test its efficacy in a immunocompetent transgenic mouse model and as well under conditions of immunosuppression (CD4 T cell deficient). The overall strategy is to use this prophylactic vaccine to stimulate the cellular (CD8+ and CD4+ T cells) and humoral responses against multiple HCMV antigens. This vaccine will be based on the novel chimeric polyepitope technology and exploits a novel replication deficient adenovirus expression system which has recently been approved for human use.Read moreRead less
Improving Efficacy Of Vaccination Against The Gut Pathogen Helicobacter Pylori
Funder
National Health and Medical Research Council
Funding Amount
$504,000.00
Summary
Helicobacter pylori are bacteria which live in the stomachs of half the World's population, where they are the main cause of two types of stomach cancers, as well as stomach and duodenal ulcers. The development of a vaccine against this organism would have a major impact on these diseases. Unfortunately, while there has been some success in animal models, the results from clinical trials have so far been disappointing. A key issue with vaccines against H. pylori is their poor efficacy, i.e. alth ....Helicobacter pylori are bacteria which live in the stomachs of half the World's population, where they are the main cause of two types of stomach cancers, as well as stomach and duodenal ulcers. The development of a vaccine against this organism would have a major impact on these diseases. Unfortunately, while there has been some success in animal models, the results from clinical trials have so far been disappointing. A key issue with vaccines against H. pylori is their poor efficacy, i.e. although they produce a significant reduction in bacteria numbers in animal models, they do not clear all of the bacteria. The remaining bacteria are sufficient to continue to cause disease. It is currently not understood how these vaccines work in mice, which makes it very difficult to improve their design. An additional problem common to all human vaccines, is the lack of a suitable adjuvant. An adjuvant is a non-specific vaccine component which is required to activate the immune system. Thus, for an effective vaccine it is essential to identify suitable adjuvants which will work against H. pylori and can be used in people. The chief investigator on this project has been working in the H. pylori vaccine field, in both academia and industry, for 8 years. He very recently identified an immunisation regime which greatly increases the effectiveness of vaccination against H. pylori in an animal model. The main aim of this project is to further develop this novel discovery to identify key immune factors that are critical to making an improved vaccine. In addition, the two associate investigators are experts in the area of adjuvants for human vaccines, and will help to test new vaccine systems in the H. pylori model. If successful, this project will generate highly significant data that will strongly contribute towards the design of an improved vaccine strategy against H. pylori in people.Read moreRead less
The world has suddenly been alerted to the threat of pandemic influenza with the recent deaths in Asia of patients and their close contacts from which the avian influenza H5N1 virus has been isolated. Experts believe that it is only a matter of time before this virus mutates and acquires the ability to rapidly spread within the human population. The currently available vaccines have virtually no capacity to prevent infection by a new pandemic virus. Once the virus strikes appropriate vaccines ca ....The world has suddenly been alerted to the threat of pandemic influenza with the recent deaths in Asia of patients and their close contacts from which the avian influenza H5N1 virus has been isolated. Experts believe that it is only a matter of time before this virus mutates and acquires the ability to rapidly spread within the human population. The currently available vaccines have virtually no capacity to prevent infection by a new pandemic virus. Once the virus strikes appropriate vaccines can be made against it but this procedure takes at least 6 months, the time predicted for the virus to have already spread throughout the globe. We are proposing that a vaccine designed to induce killer T cells (called CTLs) that target the conserved regions shared by all influenza viruses, could be used as a preventative measure without prior knowledge of the exact type of virus that will emerge. This sort of vaccine will not prevent against infection but will greatly lessen the severity of the disease. We have already designed a vaccine that that will induce high levels of CTLs that can greatly speed up the clearance of viruses of the type that are currently in the human population, when tested in animal models. However, we predict that a new pandemic virus will be much more vigorous in its growth and so our vaccines will have to be improved to cope with this. This project looks at ways of increasing the number and effectiveness of the CTLs that are induced by our vaccines. This will require an understanding of how we can modulate the function of other specialised cells, dendritic cells and helper T cells, that play a role in starting and maintaining the CTL response, as well as modulating the CTLs themselves.Read moreRead less