Burnet’s Emeritus Professor Gregory Tannock believes the science community is still ‘some way’ from developing a universal influenza vaccine that could be stored and used each year, eliminating the need to update vaccines every year.
Australia is still in the grip of the flu season with most regions reporting widespread and increasing cases to the Federal Department of Health. Notification rates in Australia this year have been highest in adults aged 85 years or older, with a secondary peak in the very young, aged less than five years.
“Flu vaccines, administered by injection, can give a healthy person up to 70 percent protection,“ Emeritus Professor Tannock said. “Although protection is less than for vaccines against other viruses, such as measles, mumps and rubella, immunisation against influenza remains a relatively cheap strategy for the prevention of influenza and should be actively encouraged.”
“Limitations of all current vaccines result from changes that occur in the strain of the virus for a particular season, resulting in a time lag of 6-9 months to produce a vaccine with an exact match to the new virus strain.
“This is a particular problem where the change is large, as occurred with the “swine” pandemic of 2009. Fortunately, the 2009 virus was not particularly virulent but the pandemic of 1918-19 was estimated to have been the cause of 40-60 million deaths! At present it is not possible to anticipate any such changes.”
With the decline in the number of viral vaccine manufacturers and low margins in profitability in recent years it also means countries will also be increasingly dependent on government subsidies to fund vaccine manufacture.
Emeritus Professor Tannock will be presenting at the 3rd Annual Microbiology and Infectious Diseases Asia Congress in Singapore in October. He also spoke with Medical News Today ahead of the Congress. The following interview has been reproduced with permission.
Microbiology & Infectious Diseases Conversations
Gregory Tannock, Emeritus Professor and Burnet Institute Visiting Fellow; Burnet Institute, Australia
A major branch of virology focuses on the classification of viruses. Do you think that the ability for a virus to evolve poses a threat to this?
There is no real evidence for this. Classification of viruses into Families is based on a wide range of very different characteristics that include size, genomic nucleic acid size, DNA/RNA, strandedness (Single or double-stranded), whether segmented or not, the presence or absence of lipid in their outer coat and type of replication. Because of this complexity, there can be no suggestion of a Linnaean classification for viruses along the lines used for vertebrates and plants.
To what extent is influenza a risk in the Asia-Pacific region? And to whom does it propose the greatest risk?
Except for avian influenza (“bird flu”), where people with exposure to live poultry are at risk, susceptibility to current influenza A and B viruses in the Asia-Pacific region does not appear to differ from that of other parts of the world. Differences may occur in rates of vaccination which are likely to be lower there and in the availability of acute hospital care for those with life-threatening infections.
Do you think there is a difference in the research undertaken in the Asia-Pacific region in comparison to say Europe or North America?
Research on influenza was, until recently, considered less important than for other viral diseases in the Asia-Pacific region. However, much has changed in recent years with the recognition that the region is a likely focus for the origin of pandemic influenza viruses, especially following direct or indirect human contact with waterbirds and subsequent genetic re-assortment that can readily occur between influenza A viruses. There are now several high quality influenza laboratories in the region and two of five World Health Organization (WHO) reference laboratories are located in Beijing and Tokyo.
At the Microbiology and Infectious Disease Congress, you will give a talk on ‘What’s New In Influenza? Progress Towards A Universal Vaccine Against Influenza A Viruses’. What do you think are the biggest challenges when it comes to a universal influenza vaccine?
I believe that we are some way from developing a universal vaccine that could be stored and used each year, making existing vaccines redundant. The problem is that the major determinant of immunity to influenza A (the cause of pandemics) is the HA spike on the outside of the virus varies continuously. That is why present vaccines have to be updated retrospectively, every year. Other parts of the virus that do not undergo variation give some protection and there is hope that they may provide some interim protection for 6-9 months until a vaccine with the “new” spike protein became available. Time will tell.
Where do you think the virology industry will be in five years time? Do you think there will be a greater move towards vaccinations as a permanent cure to certain diseases?
Unfortunately, the number of viral vaccine manufacturers has declined in recent years for reasons that are complex, and include the increasingly complex regulatory environment and declining levels of profitability. Because vaccines are universally recognised as being essential for the maintenance of public health, their continuing manufacture is heavily dependent on continuing subsidies from government in all countries. I believe these trends will continue. Most of the viral vaccines in use today (except influenza!) provide long-lasting immunity but not a permanent cure for particular diseases. However, this can be managed from booster doses.
Career and Experience:
Emeritus Professor Gregory Tannock’s current research interests include the causes of variability in the growth of influenza B viruses in eggs, development of methods for increasing yields of vaccine antigens; Development and evaluation of live attenuated vaccines against influenza (publication record over 30 years); Evaluation of broad-spectrum antiviral drugs against respiratory viruses, especially influenza and RSV; Development of improved methodologies for the rapid diagnosis of viral infections; Studies with avian viruses and, in particular, Marek’s disease virus. Emeritus Professor Tannock is a Member, Editorial Board: Journal of Medical Virology (2001-) and Biomedical Research International (2007-). Independent “voting member” (one of four) of the Australian Influenza Vaccine Committee of the Therapeutic Goods Administration, Commonwealth Department of Health. Principal Supervisor for 13 PhD, five M.App.Sc/ MedSci, 13 Honours candidates (all completed).