A phase two clinical trial of a potential cold and flu treatment has proved interferon alphas to have a significant effect on preventing and moderating winter flu.
Associate Professor Manfred Beilharz, Chair of Microbiology and Immunology (School of Biomedical, Biomolecular and Chemical Sciences), Clinical Professor David Smith (PathWest) and PhD candidate Alayne Bennett ran a trial last winter of low dose oral interferon.
Interferon is a naturally-occurring protein which inhibits respiratory viruses in most mammals. About 200 Perth people took interferon (or a placebo) every day for four months and answered a questionnaire about their health every week.
With the help of biostatistician Dr Peter Jacoby (Telethon Institute of Child Health Research), the team found that the people who took interferon had a marked reduction in the incidence and severity of symptoms of influenza.
"Among the participants who took the interferon, there was a 50 per cent reduction in moderate to severe flu symptoms," A/Professor Beilharz said. "So we achieved a primary endpoint that is highly significant."
He said the trial also demonstrated that people over the age of 50 benefitted more from interferon than younger people. "That makes good sense, because your immune system functions best when you are young. After that, it takes a bit of dive. So stimulating the immune system with low dose oral interferon alphas works better in older people."
The trial also showed that participants on the interferon who had been vaccinated against flu received a huge health benefit: a 75 per cent reduction in incidence of flu, compared with the group on the placebo.
"To respond well to a vaccine, your immune system must be firing," A/Professor Beilharz said. "And interferon did that for these people."
All 200 blood samples (taken before and after trial participation) were sent to the World Health Organisation Collaborating Centre in Melbourne, which confirmed the UWA team's results.
"Our trial has positively identified three areas in which interferon could be used against colds and flu. First, it has proved effective in protecting people from flu, and that includes the swine flu which swept through Perth as the trial was being conducted. Secondly, there is evidence that it potentiates (improves the effectiveness) of the flu vaccine, which probably means that it potentiates all vaccines, as it stimulates the immune system. Finally it also significantly reduces the incidence and severity of flu in older people who are a major risk group in relation to severe flu.
"And, on top of all that, it's cheap - probably 100 times cheaper than Tamiflu or Relenza, the current antivirals being used against pandemic flu world wide. This has important implications for public health policy." A/Professor Beilharz and his colleagues have been approached by major international pharmaceutical companies which are interested in the results.
The clinical trial was supported by the Department of Health, Sir Charles Gairdner Hospital and PathWest in conjunction with American pharmaceutical company Amarillo Biosciences Incorporated .The trial was conducted under TGA(Australia) and FDA(USA) regulation.
Published in UWA News, 28 June 2010.