Wednesday, January 16, 2013

Anticipating The Flu Season Down Under


The red band signifies the tropics, which has no distinct flu season.  Viruses circulate there, at a low level, year round. – Credit Wikipedia


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Although flu season south of the equator won’t begin for several more months, health authorities in Australia and New Zealand are watching our busy flu season closely, and are warning the public to get vaccinated in advance of what could be a difficult flu season.


Watching what happens during the flu season in the opposite hemisphere can sometimes provide clues as to what the next flu season will bring.


Of course, it doesn’t always prove predictive. 


Last year, Australia and New Zealand saw a moderately active flu season, despite North America’s unusually quiet 2011-12 flu season (see The 2012 Flu Season Down Under).


While the media coverage is a bit hyperbolic (the flu season here is being described as moderately-severe), I’ve linked to a few recent news stories from down under to provide the `flavor’ of the coverage.



Warning over killer flu

Karen O'Sullivan, Yahoo!7 January 15, 2013, 3:46 pm

Health experts are warning a deadly flu that has spread across the United States will inevitably hit our shores.

Doctors want Australians to be prepared and to make sure they are vaccinated.



The devastating flu outbreak in the US could be on its way here

  • Tory Shepherd From:
  • January 15, 2013 12:00AM
  • 20 children have died from flu in the US
  • Influenza strains travel the globe
  • Australia should consider US season a "forewarning"



NZ preparing for deadly flu

Tuesday, 15 January 2013 10:50

Medical experts in New Zealand are bracing themselves for the arrival of a deadly flu that is sweeping the US which has already killed 20 children.


The southern hemisphere flu season doesn’t usually begin in earnest until May or June, but the flu vaccine will be available starting in March. Public health officials are urging early vaccination in order blunt the flu’s impact.


Since it takes roughly six months to produce enough flu vaccine for the next flu season, twice each year (February & September) experts gather to decide on the strains to include in the next vaccine.


Last September participants from divisions of the World Health Organization’s GISRS (Global Influenza Surveillance and Response System), along with members of OFFLU (the OIE/FAO Network on Animal Influenza), and other experts met in Beijing, China.


After group consultation, the experts opted for the same vaccine formulation that is currently being used in the northern hemisphere (see WHO: Southern Hemisphere 2013 Flu Vaccine Composition).


They recommended that trivalent vaccines for use in the 2013 influenza season (southern hemisphere winter) contain the following:

  • an A/California/7/2009 (H1N1)pdm09-like virus;
  • an A/Victoria/361/2011 (H3N2)-like virus;
  • a B/Wisconsin/1/2010-like virus

They also recommended that quadrivalent vaccines containing two influenza B viruses contain the above three viruses and a B/Brisbane/60/2008-like virus.


Recent studies (see (A Comprehensive Flu Vaccine Effectiveness Meta-Analysis) have shown the flu shot to be moderately effective in preventing influenza – at least among healthy adults under the age of 65.


Similarly, last Friday in FluView Week 1 & MMWR Vaccine Effectiveness Report, we saw the first estimate of this year’s flu vaccine’s effectiveness, and early numbers suggest it to be around 62%.


For the elderly and for those with immune problems the flu vaccine’s effectiveness is often lower (see Study: Flu Vaccines And The Elderly).


In 2011, NFID - the National Foundation for Infectious Diseases - convened a group of experts to address the issues of influenza and the elderly. From that panel a 5-page brief has emerged, called: Understanding the Challenges and Opportunities in Protecting Older Adults from Influenza.



While the elderly generally see less protection from the flu vaccine, they state that older individuals may still mount a robust immune response. Even if the vaccine doesn’t always prevent infection in the elderly, studies suggest that the vaccine may blunt the seriousness of the illness in those over 65.


Although there is a pressing need for better flu vaccines (see CIDRAP: The Need For `Game Changing’ Flu Vaccines), flu shots are still considered the best preventative action you can take against influenza, and serious side effects are extremely rare.


So while not a guarantee against getting influenza, they do provide a moderate degree of protection.


Beyond the vaccine, the CDC also reminds us:


Take everyday preventive actions to stop the spread of germs.

  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub.*
  • Avoid touching your eyes, nose and mouth. Germs spread this way.
  • Try to avoid close contact with sick people.
  • If you are sick with flu–like illness, CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. (Your fever should be gone without the use of a fever-reducing medicine.)
  • While sick, limit contact with others as much as possible to keep from infecting them.

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