By Dr Jennifer Sisson*
Felt a chill in the autumn air? It’s a sign that the 2016 influenza season is approaching.
This year, two types of flu vaccine will be available from GPs, travel clinics and some pharmacies.
However, one of the two is the better choice for Australians heading overseas.
First, let me explain why there are two vaccines.
The first is the familiar 3-strain ‘trivalent’ influenza vaccine (TIV). It’s the cheaper of the two and is suitable for most healthy people. This year’s TIV formula will protect against the three principal flu strains predicted for 2016 – A(H1N1), A(H3N2), and B/ Brisbane.
The second option is a 4-strain or quadrivalent influenza vaccine (QIV), which became available in Australia for the first time last year. The additional fourth strain in this year’s QIV protects against the B/Phuket strain.
It’s this newer quadrivalent vaccine that’s the better option for travellers, according to one of Australia’s leading experts on flu, Dr Alan Hampson, the Chairman of Australia’s Influenza Specialist Group (ISG).
“Travellers are more likely to have greater exposure to A or B flu strains that are already circulating, as well as to new strains that could emerge outside Australia – especially in Asia,” said Dr Hampson.
“Plus, the B flu viruses occasionally predominate in parts of Asia. For anyone travelling overseas, having the quadrivalent vaccine makes good sense.”
Better protection for the most vulnerable
The broader protection the quadrivalent vaccine provides is the main reason it’s been chosen for Australia’s National Immunisation Program (NIP), sponsored by the Federal government.
Under the program, the vaccine is free to those most vulnerable to severe illness from flu – infants under 6 months, pregnant women, people aged over 65, and anyone with a chronic medical condition. People in these groups constitute the majority of the 2500 Australians who die on average each year from flu-related illnesses like pneumonia and the 300,000 who get so sick from flu that they need to see their doctor.
(Your doctor can advise if you are eligible for a free flu shot. If not, you can get a prescription to purchase either the trivalent vaccine or the slightly more expensive quadrivalent version.)
In most flu seasons, A-strain viruses dominate. However, the 2015 flu season was “characterised by the predominant circulation of influenza B. B/Yamagata lineage viruses and B/Victoria accounted for 62% of all lab-confirmed cases”, according to the final national Influenza Surveillance Report published in December.
Will 2016 be a repeat of 2015? No-one knows: Seasonal flu is so unpredictable that even the experts don’t know which strains will eventually come to the fore, which makes deciding on the vaccine formulation 6 months in advance (so it can be manufactured in time) such a challenge.
In my home state of Western Australia, the number of influenza cases is sitting at or just below the seasonal threshold, with 42 cases reported last week. Of these, 50% were A/H1N1, 37% were B and 13% A/H3N2 – an increase in both A/H1N1 and B since the same time last year.
For travellers, flu is hard to dodge
Flu is THE most common vaccine-preventable disease for travellers. That’s because, once you hit the road, the virus is very hard to avoid.
Here are 6 reasons why you should include a flu shot in your pre-travel immunisations:
1 – Flu is a truly global disease: it occurs seasonally in developed or developing countries, but circulates year-round in tropical regions of the world.
2 – Planes, trains, buses, cruise ships, airport terminals, hotels, crowded places, and mass gathering (concerts, major sporting events) are all higher-risk places for flu.
3 – Aircraft present a unique risk for flu because the low humidity in the cabin is very effective in spreading flu. Virus-containing particles can remain alive for up to 24 hours on hard surfaces, especially in high-traffic areas like toilets.
4 – When you are sitting for long periods in a low humidity atmosphere the mucous membranes in our nose or mouth dry out, which also increases the likelihood of acquiring respiratory infections like flu.
5 – A fellow traveller doesn’t have to have obvious signs of illness to be extremely contagious. They can pass it on for up to 3 days before their symptoms first appear and for a day or two after they recover, simply by talking or breathing.
6 – Someone in the early, mid or late stages of a flu infection can transfer virus particles from their hands to surfaces others will touch – anything from fold-down trays, arm rests or the fixtures in toilets. (Studies have shown people touch their face up to 23 times an hour and around half of those contacts involve touching the nose or mouth, where the virus enters the body.)
Flu shot is cheap ‘insurance’ – home or away
Flu has a short incubation period of 1-4 days. Getting infected early on in your journey could impact your holiday for at least a few days, forcing you to miss a planned activity or even preventing you from boarding a flight.
Finally, if you need treatment for severe flu overseas, seeing a doctor can be costly.
Don’t believe the myth that having the vaccine can give you flu. It can’t, although a small percentage of people have a mild immune response to the vaccine.
And, unfortunately, a flu shot won’t prevent you getting a cold or any of the (generally milder) respiratory illnesses that circulate during winter.
But, it is effective against flu.
Think of your seasonal flu vaccination as a form of cheap annual ‘insurance’ that covers you at home or away.
* Dr Sisson is the Acting Medical Director of Travelvax Australia.
Got a question about flu or other vaccinations for an upcoming overseas trip? Call Travelvax Australia’s telephone advisory service on 1300 360 164 (toll-free from landlines) for no-obligation, country-specific advice. You can also make an appointment at your nearest Travelvax clinic to obtain vaccinations, medication to prevent or treat illness, and accessories for your journey.