Modelling The Effects Of Immunity On Influenza Transmission - Implications For Prevention And Vaccine Development
Funder
National Health and Medical Research Council
Funding Amount
$275,767.00
Summary
There is uncertainty about how many people can be infected by a single person with influenza at the start of an outbreak. Some data suggest that a single generation of transmission can infect 10-20 other people. With such a rate of growth (ie 10-20 fold every 3 days) the spread of an influenza outbreak is virtually unstoppable. Other data suggest that each person with influenza infects less than 2 other people on average. With such a lower rate of growth, control would be more feasible. Our proj ....There is uncertainty about how many people can be infected by a single person with influenza at the start of an outbreak. Some data suggest that a single generation of transmission can infect 10-20 other people. With such a rate of growth (ie 10-20 fold every 3 days) the spread of an influenza outbreak is virtually unstoppable. Other data suggest that each person with influenza infects less than 2 other people on average. With such a lower rate of growth, control would be more feasible. Our project will use data from historic and contemporary outbreaks of influenza and build mathematical models to explain the rate of growth of an influenza outbreak in terms of: 1. The proportion of people exposed to influenza who do not become ill (although there can be evidence of infection if careful studies are made). This proportion is about 33%. 2. The proportion of people who are protected from influenza by immunity, whether induced by vaccination or by past exposure to natural influenza infection (this can vary from 0% in isolated populations which have not seen influenza for many years up to 80 or 90% in urbanised populations that are exposed to influenza almost every season). 3. Different rates of contact between different people and groups of people - some may be exposed so often that their immunity is boosted regularly without them becoming severely ill; others, living in more isolated circumstances, may be rarely exposed, but when they are, they are more likely to become severely ill. 4. The effects of influenza vaccine in inducing protective immunity - it is well known that there is good protection if the vaccine is well matched to the circulating virus. 5. The effects of live virus infection in inducing (short-lived) protection against a wider range of influenza viruses. Our model results will be used to guide vaccine design and pandemic planning.Read moreRead less
Long Term Persistence Of HIV In The Liver And The Clinical Impact On HIV-HBV Co-infection
Funder
National Health and Medical Research Council
Funding Amount
$1,393,245.00
Summary
This grant will address a major question in HIV cure research - the role of the liver as an HIV reservoir and the impact of HIV persistence in HIV-infected patients on suppressive antiretroviral therapy (ART) on liver disease, in the setting of HIV-HBV co-infection. We will trial a novel intervention to reduce HIV infection of the liver that could potentially reduce chronic liver disease in this setting.
A New Model For The Pathogenesis Of Rheumatic Fever: Superantigen Priming Of The Immune Response To Group A Streptococci
Funder
National Health and Medical Research Council
Funding Amount
$248,820.00
Summary
Acute rheumatic fever (ARF) is now rare in developed countries. However, it remains a major problem in Aboriginal Australians in the NT where the rate of ARF is the highest in the world. This leads to high rates of rheumatic heart disease (up to 3% of individuals in some communities) and a premature mortality of over four times that for developing countries. Immunisation and improved living conditions offer a long-term solution but these remain a distant prospect. In the short and medium term, c ....Acute rheumatic fever (ARF) is now rare in developed countries. However, it remains a major problem in Aboriginal Australians in the NT where the rate of ARF is the highest in the world. This leads to high rates of rheumatic heart disease (up to 3% of individuals in some communities) and a premature mortality of over four times that for developing countries. Immunisation and improved living conditions offer a long-term solution but these remain a distant prospect. In the short and medium term, control of this ARF will partly depend on new and better treatment and prevention strategies. To achieve these goals a deeper understanding of the immune mechanisms underlying this disease is urgently needed. It is known that ARF is caused by an abnormal immune response following streptococcal infection. This leads to the production of cells called T cells that attack the body s own tissues rather than the bacteria itself. This autoimmune disease is responsible for the heart damage that underlies ARF. It is believed that this proces only occurs when susceptible individuals are infected with specific rheumatogenic strains of streptococci. However there are a number of deficiencies in this model and it is proposed that there is an additional factor responsible for the abnormal immune response in ARF. This project will explore the possibility that bacterial toxins called superantigens are the critical missing factor , by studying the immune response in ARF. Superantigens are produced by certain streptococci and staphylococci, and are potent in minute quantities causing widespread activation of the immune system. They have been found to play an important role in a number of autoimmune diseases and the type of immune response found in ARF fits well with that expected if superantigens were involved. If superantigens play an important role in causing the abnormal immune response in ARF then a number of new avenues would open for the treatment and prevention of this disease.Read moreRead less