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The 2017 Influenza Vaccine

by Dr Bob Kass - March 6, 2017

The media is already starting to bombard you with news on the 2017 influenza vaccine. 

Is this important from a health perspective? Do you respond favorably to these reports or do you just turn off, thinking it’s just another beat up to spruik sales for pharmaceutical companies. 

Any discussion on influenza is important for those over 65 or with pre-existing health issues which could result in severe infection. It should always be part of any travel consultation.

When Australia is in the “low season” (November to April) the intending traveller is often heading into the northern hemisphere peak season. On the other hand, if travelling out of Australia during our risk period (May to October) the traveller may start out unwell and may not be a welcome participant on a group tour. Most regular group travellers will have experienced this scenario in the past.

At Globe Medical we regularly see the consequences of respiratory tract infections in returned travellers.  It must be remembered that giving a flu vaccine doesn’t prevent all upper respiratory tract infections. At least we have an option available to prevent serious disease which may cause hospitalization or loss of holiday or business time overseas or on return.

Prevention of flu and other respiratory tract disease shouldn’t end with a jab. If this is the case then find someone else for your travel advice! Prevention is mostly about hand care and this should never be trivialized. Hand sanitisers DO work. Always carry a small container in a clear plastic bag. After clearing airport security, place it in your pocket for easy use at all times.

[SHOP NOW for Hand Sanitiser at Globe Medical's Travel Shop]

The 2017 formulation

The 2017 formulation will be a quadrivalent vaccine including 2 strains of Influenza A and 2 for B.

The following strains have been included:

  • A/Michigan/45/2015 (H1N1) pdm09 - like virus  (new in 2017)

  • A/Hong Kong/4801/2014 (H3N2) - like virus

  • B/Brisbane/60/2008 - like virus

  • B/Phuket/3073/2013-like 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 2016.

The following observations were made:

  • Peak activity occurred during September (see below)
  • Notifications were lower than in the previous year
  • Influenza A dominated throughout the season with A (H1N1) early and A (H3N2) throughout from July.
  • Notifications were high in those over 75 years
  • There was a good match for the seasonal vaccine and circulating virus strains
  • There were fewer admissions but a higher proportion of severe disease.

report of consultation rates for flu like illnesses in 2016

From CDI Vol 40, Number 4 December 2016

Influenza activity in North America (2016-17 season)

Flu activity was moderate for the flu season in North America.  Peak activity has been reached and now starting to fall. The vaccine formulation was a good match for the circulating strains and correlates well with the quadrivalent vaccine to be used in Australia this winter season.

Recent activity in Australia (2017).

Influenza activity never totally disappears in Australia. Cases do occur even in the middle of summer. It is always possible for a returning traveller to start a cluster of cases at any time. The world is a small place.

SA Health has recently reported a higher number of cases year to date, than in 2016. Major outbreaks at this time of year are still unusual.

About Influenza

Influenza viruses spread person to person by droplet infection and small particle aerosol.  Droplets generally travel only a smaller 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.

PREVENTION

The administration of an influenza vaccine to persons at risk is the most important measure to prevent influenza illness and its severest complications.

Prevention for Travellers

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! Don't forget to take some hand gel.

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Author

Dr Bob Kass

Dr Bob Kass is Medical Director of Globe Medical. He holds specialist qualifications in paediatrics and public health medicine and is one of Australia's pioneers in the discipline of Travel Medicine. 

Full professional biography | Book an Appointment with Dr Kass