Seeking Best Swine Flu Defence
First Published: Investigator - July 2009
Up to 100 people with confirmed cases of seasonal flu and swine flu will take part in a new study at Flinders Medical Centre to investigate how the body protects itself against the viruses.
The study will examine the immune response to normal seasonal influenza and the newest strain of influenza A - human swine influenza H1N1 (swine flu).
Head of Microbiology and Infectious Diseases at SA Pathology, Flinders Medical Centre and Flinders University Professor David Gordon said the study will have major benefits for predicting the likely spread of influenza strains in the community.
‘The findings will also be very important in planning vaccination programs against new strains of influenza,’ he said.
Researchers will identify study participants from laboratory results at Flinders Medical Centre. A sample of blood will be taken 2-3 weeks apart - once at the time of infection and two weeks later - to measure influenza antibodies which are formed in response to infections or vaccinations.
‘If people form an antibody response (protective immune response) we will be interested to see how long that antibody lasts, or whether it disappears,’ Professor Gordon said.
A second part of the study will answer questions about cross protection against other forms of influenza.
‘We will be looking at whether antibodies to swine flu are formed after infection, how long they last and if antibodies from people with seasonal influenza can provide cross-protection against swine flu.
‘There is also some suggestion elderly people may have protection against swine flu, so we are interested to know if there is background immunity in this population.’
Professor Gordon and his team at Flinders have developed a unique way to use a test known as an assay to accurately measure antibodies that form in response to swine flu or seasonal flu.
‘In the case of influenza A, antibodies against a surface protein of the virus called haemagglutinin form during infection and result in long term protection against re-infection with that particular influenza A strain,’ he said.
‘We have developed a method where we can get cultured cells to express cloned seasonal or swine haemagglutinins on the outside of their surface, enabling measurement of antibodies against these proteins.
‘If antibodies are detected that bind to these cells it means they are reacting against a particular haemagglutinin which almost certainly means immunity.’