2016 Flu Vaccination - Key Facts
Two different vaccine formulations will be available in Australia for 2016. One contains the usual three strains of influenza virus (trivalent) and the other is a 4 strain (quadrivalent) vaccine. It is important for you to understand the difference.
The 2016 trivalent formulation contains the following strains:
A/California/7/2009 (H1N1) pdm09 - like virus
A/Hong Kong/4801/2014 (H3N2) - like virus
B/Brisbane/60/2008 - like virus (belonging to the Victoria lineage)
The quadrivalent vaccine contains an extra B component. The quadrivalent vaccine was available for the first time in 2015 and will be the preferred formulation for those over 65 years in 2016. Those most at risk for serious disease.
It contains the above strains included in the trivalent plus an extra B strain (below):
- B/Phuket/3073/2013-like virus
Trivalent influenza vaccine has been available in Australia since the late 1970s. It includes two strains of Influenza A and one of influenza B virus. Influenza A and B are distinctly different viruses and B, unlike A, does not circulate in animals, only in humans. Influenza B also tends to cause milder illness, is less diverse (mutates more slowly than A) and is not normally associated with epidemics. Immunity to influenza B is usually acquired in early life. In 2015, the higher than usual number of notifications was largely due to Influenza B in children.
The influenza A vaccine is classified by surface proteins Haemagglutinin (HA) and Neuraminidase (NA). Every year WHO (World Health Organisation) provides advice on the components of the vaccine for the coming influenza season. This advice is usually provided in September for the southern hemisphere and February for the northern hemisphere. The advice is based on sentinel monitoring of laboratory confirmed influenza cases around the world.
Recommendations are based on “best fit” strains to protect against the circulating influenza viruses noted during the previous winter in the southern hemisphere and those in the inter-season northern hemisphere period.
Australian influenza activity in 2015
The following observations were made:
Peak activity occurred during August
Notifications were higher in the childhood population than in previous years
Strain B accounted for higher level of notifications than in previous years. Influenza A (H3N2) was three times more common than Influenza A (H1N1) in those typed
Despite higher levels of flu activity, clinical severity appeared less than in previous years.
Australian Influenza Surveillance Report No. 10, 2015
Influenza activity in North America
Much criticism was made of the vaccine provided for the 2014/15 season. It was estimated to have a protective efficacy of less than 20%. This is not the case for the 2015/16 season. Good protection of almost 60% has been observed for both A and B. The currently recommended Australian vaccine is a good fit for the season recently experienced in the USA.
Influenza viruses spread person to person by droplet infection and small particle aerosol. Droplets generally travel only a short distance (< 2 metres) while aerosol may go further.
The virus replicates in, and infects adjacent cells of, the upper respiratory tract. Local mucosal immunity develops and there is a rise in serum antibodies.
Individuals are most contagious in the first 3 days after the onset of symptoms but probably shed the virus for about 5 days. A person also can be infectious the day before they develop symptoms. Those who are immune-suppressed or who have chronic disease shed the virus for longer. The virus can remain viable for hours in dried secretions before transfer to the respiratory tract. The incubation period (time between exposure and symptom onset) is 1 to 2 days.
About 1,500 Australians die from the complications of influenza every year. Most of these are over 65 years or under 5 years of age. Many have contributing health factors which make the illness worse. There are approximately 13,500 hospitalisations and 300,000 GP consultations every year in Australia due to influenza virus.
Assessment of Risk
There is constant global influenza presence but exposure risk for the individual depends on many factors such as time of travel, type of travel and activities relating to the trip. Infection rates are highest in children (likely non immunes) and the rates of severe illness are highest in those over 65 years (hence the free national immunization program for that group).
Attack rates are high in susceptible crowded populations. This can be as high as 40% in closed settings such as a school, retirement village or nursing home. Cruise ships are such a setting.
The peak virus activity is in the winter months in temperate climates and during the dry season of the tropics and subtropics.
The administration of an influenza vaccine to persons at risk is the most important measure available to prevent influenza illness and its severest complications.
Travellers are always at risk due to increased exposure in airports, commuter transport and other crowded areas. They may be elderly and many have significant co-morbidities.
Travellers should also be reminded of the importance of hand hygiene to reduce the risk of contracting influenza and other influenza-like viruses. Surfaces can easily be contaminated.
Have a flu jab and enjoy your travels! ...... plus take some hand gel
Benefits of attending a vaccination centre for my flu jab.
We are often asked why an individual should come to a vaccination centre like Globe Medical rather than attend the local chemist or a workplace vaccine program. The following reasons stand out:
Flu vaccine like any vaccine should be undertaken by professionals who regularly administer vaccines. It should also be provided in an environment where a faint or adverse reaction can be best managed. Not everyone will admit to a previous faint and in many non-clinic situations individuals are vaccinated in a chair rather than on a couch.
Globe Medical has provided routine and travel vaccines for many years. The clinic is separated into 2 areas, one for those presenting for general practice and another for those who are currently well and are seeking preventative health advice or immunization. It has worked well over many years.
Providing an influenza vaccine is just one way we can reduce morbidity in the wider population. Other vaccines may be indicated. During a vaccination centre visit the individual is able to seek further information on; dTpa (triple antigen), Pneumovax (pneumonia), MMR (particularly for those born between 1966 and 1980), chickenpox and shingles to mention a few routine immunisations. Other information on ways to reduce flu or flu-like morbidity during the winter season can also be discussed. The importance of hand sanitisers in the workplace is particularly important.
The Globe Medical team also believes that vaccine records are very important. The clinic is able to establish a permanent digital record and make it readily available should it be required in the future.