By Dr Eddy Bajrovic*
Not sure about getting the flu vaccine this year?
These flu facts might convince you that it’s a sensible idea – especially if you’re travelling overseas.
FLU FACT: Flu is a higher risk for travellers.
Flu is THE most common vaccine-preventable travel disease – regardless of whether you’re visiting a developed or developing country, or if it is the flu season there or not. In tropical regions, flu circulates year-round and travellers bring different strains from all points of the compass.
FLU FACT: It’s highly contagious and very hardy.
Most people get flu when an infected person coughs or sneezes, leaving tiny droplets containing the virus suspended in the air waiting to be inhaled. But, the flu virus can survive for as long as 24 hours on any hard surface in aircraft cabins, airport terminals, taxis/trains/buses/ships, and just about any crowded place you find yourself during your journey.
FLU FACT: Everyone can get flu – protect the most vulnerable.
No-one is immune from flu: Even young, fit people are felled by flu. However, it’s more likely to be severe for infants, the elderly, and people with immune suppressive disorders or chronic medical conditions. Pass it on to someone vulnerable at home or on holiday and you could make someone close to you very sick.
FLU FACT: Flu can be deadly.
Flu kills an average 2500 Australians each year – about the same number as die on the nation’s roads. Another 300,000 need to see their GP for treatment, while 18,000 are hospitalised, an Australian study found.
FLU FACT: It can stop an overseas trip in its tracks.
Flu isn’t a bad cold: You won’t shrug it off with a hot lemon drink and paracetamol. It can take up to two weeks to fully recover, possibly stopping you from boarding a flight or disrupting your holiday activities. (And, if you need treatment for flu while you’re away, seeing a doctor overseas can be costly.)
FLU FACT: You can’t get the flu from the vaccine.
This myth persists, but it simply isn’t true. To prime your immune system, the vaccine contains purified and inactivated (‘killed’) influenza virus. The vaccine generally contains three strains of inactivated influenza virus predicted to be circulating in the coming flu season. The vaccine CANNOT give you the flu or a cold.
Some important things to note
If you get sick after having the vaccine, there may be several possible causes: It simply may not be the flu virus. If it is, you were almost certainly exposed to the virus before you were vaccinated, or in the 14 days it takes for the vaccine to reach peak strength. You may also have been infected with a strain not included in the vaccine.
It’s also important to note that the vaccine is not without possible side effects. The most common are mild fever, malaise, and muscle aches, which occur in 1-10% of vaccine recipients. These symptoms are generally mild and resolve within 1 to 2 days but rare cases of febrile convulsions can occur in children under the age of 5. Local adverse reactions like soreness and swelling at the injection site occur for around 1-in-10 people.
‘Drift’ reduced vaccine’s effectiveness
Making the flu vaccine (or any vaccine for that matter) is a complex, high-tech affair. The reason doctors advise getting vaccinated every year is because each new flu vaccine targets the dominant strains expected to be circulating in the upcoming flu season.
Experts from the WHO have to identify the specific strains early enough to give the pharmaceutical companies 6 months to develop the vaccine and produce sufficient doses to go around.
This process usually goes to plan, but not always.
In the northern winter just ended, the genetic code of one of the three flu strains included in the vaccine ‘drifted’ (mutated) just enough in that 6-month period to make the vaccine only around 23% effective. The mismatch between the vaccine and the flu strains contributed to a more severe 2014-15 flu season across the northern hemisphere.
Northern flu season ‘severe, prolonged’
In the USA, the flu season has been the most severe and prolonged for some time due to H3N2 infections, while swine flu has been responsible for high death rates in Hong Kong and India. The WHO is ‘carefully watching’ India’s swine flu outbreak after 19,000 confirmed cases and 1041 deaths.
For Australia, the vaccine formulation recommended by WHO in September included two new strains, one an updated version of the H3N2 virus which will cover the strains seen recently in the Northern Hemisphere.
Each strain change presents problems and potential delays for regulatory authorities and vaccine manufacturers and this year the double strain change has caused a supply delay that is likely to postpone the launch of Australia’s 2015 National Seasonal Influenza Immunisation Program from March to April,Australia’s drug regulatory authority has advised.
Southern vaccine ‘a good match’
The good news is that the mutation has been addressed in this year's Southern Hemisphere vaccines, which should be a good match for the viruses in circulation.
2015 is the first year that both trivalent (three-strain) vaccines and quadrivalent (four-strain) vaccines will be available in Australia. The more expensive quadrivalent vaccines contain the same strains as the trivalent vaccines, plus a second influenza B strain.
“All available data indicates that we won’t face a situation like the Northern Hemisphere countries did,” flu expert, Dr Alan Hampson, Chairman of the Influenza Specialist Group, told Travelvax Australia.
“The vaccine should offer Australians good protection this winter.”
Delay in arrival of vaccine
However, the delay will reduce the time available to get vaccinated before the peak flu season gets underway.
To date, there have already been more than 1258 cases of influenza notified in Australia – well above average for this time of year.
Queensland has been hardest hit with nearly lab-confirmed 500 flu infections in January, although many others went undetected.
Free flu vaccine is available in Australia for people aged over 65, Aboriginal and Torres Strait Islander people aged 15 and over, pregnant women, anyone aged 6 months and over with heart disease, severe asthma, a chronic lung or other illness, diseases of the nervous system, impaired immunity, or diabetes.
Frequent flyers at higher flu risk
A growing number of Australian employers are offering all of their employees free on-site vaccination, protecting both their businesses’ main assets and the company’s bottom line.
But, it’s especially important for business travellers and other frequent flyers to be immunised against flu, particularly if their work takes them to places in the world experiencing an influenza outbreak.
The flu vaccine protects for 6-12 months, so vaccination should protect regular travellers during and after our flu season.
Kids can have severe infections
During flu outbreaks, more children get sick than adults. (Medical science isn’t sure why – it could be because adults have some residual immunity from earlier bouts of flu and/or from having been vaccinated in the past.)
Children younger than six months (who are too young to be vaccinated) are more susceptible and tend to have severe cases.
Kids also harbor the virus for longer than adults, making them a major source of transmission during outbreaks – at home or during holidays.
Handy tip for avoiding flu
Travelling or not, you can minimise the risk of flu this winter by regularly cleaning your hands with soap and water, or using alcohol-based hand sanitisers or wipes if they are not available.
Hand hygiene reduces your chances of picking up or passing on flu, as well as other viruses and bacteria (including those that cause traveller’s diarrhoea).
Some hand sanitisers include natural products and essential oils that moisturise and condition the skin.
Just check that the one you choose contains the 60% alcohol needed to kill germs.
Read more on how to protect yourself against the flu.
* Dr Bajrovic is the Medical director of Travelvax Australia.
Get expert advice on healthy travel by calling Travelvax Australia’s free advisory service on 1300 360 164.