Infuenza Specialist Group

December 2008

Influenza outbreaks in nursing homes are not reported to health authorities in 9 out of 10 cases, and low vaccination rates among staff are fuelling their spread. Influenza is potentially fatal to elderly people, but a three-year study by Australian experts has found that while only 2 per cent of nursing homes each year report having a flu outbreak, the real figure is over 20 per cent. Although over 90 per cent of residents were immunised, the researchers say the vaccine's slightly lower efficacy in older age groups means it is still possible for the infection to spread through nursing homes once it finds a way inside. Lead researcher Robert Booy, head of clinical research at the National Centre for Immunisation Research and Surveillance, told a recent conference in Sydney that the "reason flu gets brought in is because staff have relatively low rates of vaccination - perhaps 20 per cent of staff are vaccinated, and you need at least a 50 per cent uptake among staff to protect residents".

Content Updated (Tuesday, 6th January 2009)

 December 2008

According to a recent study (Nature. 2008 Dec 18;456(7224):985-8), the H5N1 flu virus avoids natural cell defences by hiding bits of its genetic material that would normally trigger an infection alarm. Pieces of protein inside the virus form tube-like structures that obscure strands of viral RNA formed as host cells are attacked. The finding may explain why this strain of bird flu is so deadly in people, and could lead to drugs that will unmask the virus and let our natural defences do their job. Earlier research had shown that the so-called NS1 protein played a key role in H5N1's virulence. Images from a cryo-electron microscope revealed that the proteins (when "crystallised") interact to create tiny tubes, hiding the RNA (generated during infection) that would normally prompt the body's immune system activate. It is hoped that an NS1 "library" could be built once other NS1 structures from other influenza viruses have gone through the same process.

Content Updated (Tuesday, 6th January 2009)
 

November 2008

A study (Pediatrics. 2008 Nov;122(5):911-9) showed that even in an influenza season where there is not an optimal match between circulating strains of influenza and the strains contained in the influenza vaccine, the vaccine is likely to significantly protect young children, ages 6 to 59 months, against influenza. There was a 57-percent reduction in influenza-related medical visits in the children who received all recommended doses of the influenza vaccine compared to unvaccinated children in one of the two influenza seasons studied (2004-2005). Children 6 months up to 9 years of age need to have two vaccine doses if they are getting a flu vaccine for the first time. The study found no protection against flu for children who needed two vaccine doses and only received one.  

Content Updated (Tuesday, 6th January 2009)

November 2008

A study from Utrecht, Netherlands (Plos Medicine, 2008;5(10):1453-1460) noted that while annual influenza vaccination of health care workers (HCWs) is advised in most Western countries, adherence to this recommendation is generally low. Although protective effects of this intervention for nursing home patients have been demonstrated in some clinical trials, the exact relationship between increased vaccine uptake among HCWs and protection of patients remains unknown owing to variations between study designs, settings, intensity of influenza seasons, and failure to control all effect modifiers. Using a mathematical model to estimate the effects of HCW vaccination in different scenarios and to identify a herd immunity threshold in a nursing home department, the researchers used a stochastic individual-based model with discrete time intervals to simulate influenza virus transmission in a 30-bed long-term care nursing home department. The model revealed a robust linear relationship between the number of HCWs vaccinated and the expected number of influenza virus infections among patients. In a realistic scenario, approximately 60% of influenza virus infections among patients can be prevented when the HCW vaccination rate increases from 0 to 100% vaccination. A threshold for herd immunity was not detected.

Content Updated (Tuesday, 6th January 2009)

The Flu Tracking Project is a pilot health surveillance system to detect epidemics of influenza.

Established by the Hunter New England Area Health Service and the NSW Government, the project seeks people who live in Australia and have easy access to email and the internet on a weekly basis. Participants spend about 10-15 seconds per week to respond to an email about symptoms they, or other household members, may have had in the previous week.

Participation is voluntary and the information remains confidential.

If you wish to participate, please use the the Flu Tracking Project link.

August 2008

A study by the British Health Protection Agency found annual influenza vaccination in children could cut some types of the disease by up to 70 per cent. It called for all children under the age of two to be vaccinated to prevent the spread of disease in the community and to offer added protection to those at risk of developing serious complications from the virus. Influenza Specialist Group chairman Dr Alan Hampson said routine vaccination of children could help curb the spread of influenza. "There is a lot of evidence that vaccinating children is beneficial and there's a lot of evidence that children are major spreaders of influenza,'' Dr Hampson said. He added that while a case could be mounted to vaccinate very young children, it might nevertheless be difficult to mount a pharmacoeconomic argument for a government funded program.

Content Updated ( Wednesday, 3rd September 2008)

August 2008

New research by American scientists  has revealed that antibodies from survivors of the 1918 flu pandemic, the worst in human memory, still protects against the deadly virus. The findings detailed in the journal Nature (Neutralizing antibodies derived from the B cells of 1918 influenza pandemic survivors, Yu et al,  (http://dx.doi.org/10.1038/nature07231) report that the immune systems of the pandemic survivors, still alive today, carry a memory of that virus and can produce antibodies that kill the 1918 flu strain with surprising efficiency.  "It was very surprising that these subjects would still have cells floating in their blood so long afterward," said Dr. James Crowe of Vanderbilt University in Tennessee, who helped lead the study. "The antibodies that we isolated are remarkable antibodies. They grab onto the virus very tightly and they virtually never fall off," Crowe said in a telephone interview. "That allows them to kill the 1918 virus with extreme potency, meaning it takes a very small amount of antibody.

Content Updated ( Wednesday, 3rd September 2008)

August 2008

The National Drugs and Poisons Committee announced this month its decision to maintain the current prescription only (S4) scheduling of oseltamivir, a treatment for seasonal influenza. A submission made earlier this year to the Committee regarding the rescheduling of oseltamivir to a pharmacist only (S3) medication instigated the Committee's review. The Committee concluded at its June meeting that a rescheduling was unnecessary as state governments were putting in place legislation and regulation to extend access to the drug during an influenza epidemic. The decision to keep oseltamivir on prescription rather than down-schedule it to S3 was made despite the majority, ten out of fourteen submissions received, being in favour of a down-scheduling.

Content Update (Wednesday, 3rd September 2008)

August 2008

A study undertaken at the National Centre for Immunisation Research and Surveillance (NCIRS) at Westmead together with several GP practices  has demonstrated that providing influenza vaccination intradermally produces a stronger immune response compared with the traditional intra muscular vaccination route for elderly patients. Using a new microinjection system, the NCIRS researchers compared the different vaccination delivery methods in more than 1,100 volunteers aged 60 years and older. The study is reported in the Journal of Infectious Diseases (198:650-658).

Content Updated ( Wedensday, 3rd September 2008)

June 2008

An Australian-developed and manufactured avian influenza vaccine has received TGA approval in Australia. The TGA announced on 17 June that it had approved the licence for Panvax, manufactured by CSL, for use in the prevention of influenza caused by a pandemic strain of the avian influenza virus. "The vaccine, Panvax, protects humans against the H5N1 influenza virus, which has been responsible for outbreaks of avian influenza in Asia, the Middle East, Europe and Africa," Health Minister Nicola Roxon said in a statement. Three randomised, double-blind clinical studies were conducted to assess the safety of the vaccine in adults aged 18-64, and older adults aged 65 years and over, Roxon said. The vaccine, is administered in two doses and can only be used once an influenza pandemic has been officially declared by the World Health Organisation.

Content Updated (Wednesday, 9 July)