What is Influenza?
Influenza A and B are the major types of influenza viruses causing human upper respiratory disease. Classic symptoms include fever, lethargy, muscle aches and pains and a cough. Antibiotics are ineffective against the influenza virus.
Where is it found?
Epidemics of influenza occur during the winter and spring months in most years. The virus causes disease in all age groups, but while rates of infection are highest among children, serious illness and death is more common with the elderly and persons of any age who have medical conditions that place them at high risk for complications. Influenza viruses can also cause global epidemics of disease, or pandemics, during which rates of severe illness and death from influenza-related complications can increase dramatically.
Risk to travellers
The risk for exposure to influenza during travel to foreign countries varies depending on the time of year and destination: In the tropics, influenza can occur throughout the year; in the southern hemisphere, most activity occurs from April through September, while in the northern hemisphere peak activity occurs from November through March.
In recent years, influenza strains originating in birds have sickened humans in various parts of the globe including China, Indonesia and Egypt. Fortunately, transmission of the viruses between humans has been rare to date, however the possibility of a mutation of the viruses allowing for further spread remains. Advice for travellers to areas affected by avian influenza outbreaks includes: avoid animal markets, don’t touch animals/birds, eat only well-cooked chicken & eggs and practice good personal hygiene. Recommendations for travellers to countries experiencing avian influenza outbreaks can be found at smartraveller.gov.au.
Travelvax recommends vaccination against influenza be considered for travellers who:
are over 65 years of age.
have a chronic heart or lung condition.
travel with large tourist groups (particularly trains, buses, cruise ships).
business travellers who wish to avoid lost time.
NB - Vaccination is recommended every 12 months. If travelling to a different hemisphere, the types or strains of flu virus circulating may differ from the hemisphere from which you have travelled. If you have been vaccinated recently against influenza, it is advisable to check if the strain of the virus at your destination is covered by the vaccine you have received.
What is Influenza Vaccination?
Inactivated virus vaccine - intramuscular
- Single dose annually - adult and child formulations.
- For infants & children aged 6 months to 10 years who have never had the vaccine before: 2 doses at least 4 weeks apart.
- Single dose annually of high dose or adjuvanted trivalent vaccines for people aged over 65 years
Contraindications: People who have previously had an allergic reaction following an influenza vaccine or component of an influenza vaccine.
Those individuals with known anaphylactic hypersensitivity reactions to egg proteins (eggs or egg products) or chicken proteins should discuss with a doctor whether administration of the vaccine may be conducted under special conditions (as per the Australian Immunisation Handbook).
Level of protection
6 to 9 months protection against main influenza viruses each season. (Will not protect against the common cold viruses.)
Possible Side Effects
- Usually infrequent and mild
- Soreness at the injection site in around 10% of vaccinees
- 15- 20% may experience fever, lethargy and muscle aches
- High dose or adjuvanted trivalent vaccines produce injection site reactions in around 30% of vaccinees.
NB: Contrary to popular myth, none of the influenza vaccines are live so cannot cause influenza.
As with all vaccines, there is a small risk of allergic reaction.