What is influenza (flu)?
Influenza is a highly infectious acute respiratory illness caused by the influenza virus. Influenza affects people of all ages. Outbreaks of influenza occur almost every year, usually in winter. This is why it is also known as seasonal flu.
How serious is flu?
Flu is often self limiting with most people recovering in 2-7 days. However, flu can be severe and can cause serious illness and death, especially in the very young and in the elderly. Serious respiratory complications can develop, including pneumonia and bronchitis, to which older people and those with certain chronic medical conditions are particularly susceptible. Pregnant women have also been found to be at increased risk of the complications of flu. Some people may need hospital treatment and a number of mainly older people die from influenza each winter.
How do people catch flu?
Flu is a highly infectious illness. A person carrying the virus can spread the illness by coughing or sneezing. A person can spread the virus from 1-2 days before they develop symptoms and for up to a week after symptoms develop.
What are the symptoms of Flu?
Flu symptoms hit you suddenly and severely. Symptoms of flu include
Is it seasonal flu or the common cold?
It can be difficult at times to tell between the common cold and flu. A cold is a much less severe illness than flu. The flu symptoms come on suddenly with fevers and muscle aches. A cold usually starts gradually with symptoms of a sore throat and a blocked or runny nose.
Table of Symptoms
The following table provides information on how to distinguish between seasonal flu and cold symptoms.
| Symptoms |
Seasonal flu |
Cold |
| Fever |
High fever lasts 3-4 days |
Rare |
| Headache |
Prominent |
Rare |
| General Aches, Pains |
Usual; often severe |
Slight |
| Fatigue, Weakness |
Can last up to 2-3 weeks |
Quite mild |
| Extreme Exhaustion |
Early and prominent |
Never |
| Stuffy Nose |
Sometimes |
Common |
| Sneezing |
Sometimes |
Usual |
| Sore Throat |
Sometimes |
Common |
| Chest Discomfort, Cough |
Common; can become severe |
Mild to moderate; hacking cough |
Who is most at risk from flu?
Anyone can get the flu but it is more severe in people aged 65 years and over and anyone with a chronic medical condition. Chronic medical conditions include chronic heart conditions, chronic respiratory disease, diabetes mellitus and immunosupression due to disease or treatment. Pregnant women have also been found to be at increased risk of the complications of flu. These groups of people are targeted for influenza vaccination.
How can flu be prevented?
Flu can be prevented by vaccination. Flu vaccine is a safe, effective way to help prevent flu infection, avoiding hospitalisation, reducing flu related deaths and illnesses.
What is the seasonal (annual) flu vaccine?
Each year the seasonal (annual) flu vaccine contains three common influenza virus strains. The flu virus changes each year this is why a new flu vaccine has to be given each year. This year’s flu vaccine contains the Swine Flu strain.
What strains are in this year’s seasonal flu vaccine?
This year’s seasonal flu vaccine contains 3 strains of flu viruses as recommended by the World Health Organization (WHO) and has been manufactured in a similar way to previous seasonal vaccine. The three strains are
A/California/7/2009 (H1N1)-like virus (the pandemic H1N1 2009 virus) an A/Perth/16/2009 (H3N2)-like virus; a B/Brisbane/60/2008-like virus
Who should be vaccinated?
Vaccination is strongly recommended for:
persons 65 and over, those with a long-term medical condition such as diabetes, heart or lung disease, people whose immune system is impaired due to disease or treatment, healthcare workers, residents of nursing homes and other long stay institutions, persons with a body mass index (BMI) over 40, pregnant women. (can be given at any stage of pregnancy), carers people with regular close contact with poultry, water fowl or pigs.
How does seasonal flu vaccine work?
Seasonal flu vaccine helps the person’s immune system to produce antibodies to the flu virus. When someone who has been vaccinated comes into contact with the virus these antibodies attack the virus.
What is Swine Flu?
Swine Flu is a new flu virus that first emerged in April 2009. As most people did not have any immunity against this virus it spread rapidly worldwide and infected a large number of people. It is also known as Pandemic H1N1 (2009). Swine Flu infected in particular young children, pregnant women, women up to 6 weeks after giving birth and those under 65 years with long term medical conditions.
Why is the Swine Flu strain in this year’s vaccine?
It is likely that the Swine Flu strain will be the predominant strain circulating this season. However we cannot be 100% certain of this and the WHO makes its recommendations based on expert advice and this is why the seasonal flu vaccine offers protection against three strains.
How long is the flu season?
In the Northern hemisphere the flu season lasts from October to the end of April. Flu vaccine is recommended for all those in the at risk groups until the end of April Women who become pregnant at ant stage during the flu season should get flu vaccine.
How safe is flu vaccine?
Seasonal flu vaccines have been given for more than 60 years to millions of people across the world. Reactions are generally mild and serious side effects are very rare. The seasonal flu vaccines cannot give you the flu.
What is thiomersal?
Thiomersal is a mercury-containing compound that has been used since the 1930s to prevent contamination in some vaccines. Thiomersal is NOT the same as methyl mercury, which can accumulate in the body and become toxic. A European review of the available evidence concluded that there is no evidence of harm from thiomersal in vaccines other than hypersensitivity reactions. The WHO has concluded that there is no evidence of mercury toxicity in infants, children, or adults exposed to thiomersal in vaccines.
Is there thiomersal in the seasonal flu vaccine?
No. There is no thiomersal in the vaccine used in the 2011/2012 flu campaign
Will the flu vaccine give me the flu?
No, flu vaccine will not give you the flu. Flu vaccine contains killed or inactivated viruses and therefore cannot cause flu. It does, however, take 10 – 14 days for the vaccine to start protecting against flu.
When should I get vaccinated?
The vaccine should be given in late September/October each year.
What should I expect after vaccination?
The most common side effects will be mild and will include soreness, redness or swelling where the injection was given. Headache, fever, aches and tiredness may occur. Some people may experience mild sweating and shivering as their immune system responds to the vaccine but this is not flu and will pass in a day or so.
How long does it take the vaccine to work?
The vaccine starts to work within two weeks.
Who should NOT get seasonal flu vaccine?
The vaccine should not be given to those with a history of severe allergic (anaphylaxis) reaction to a previous dose of the vaccine or any of its constituents.
What about people with egg allergy?
People with egg allergy can get seasonal flu vaccine. This may be given by your GP or you may need referral to a hospital specialist.
When should vaccination be postponed?
There are very few reasons why vaccination should be postponed. Vaccination should be re-scheduled if you have an acute illness with a temperature greater than 38°C.
What about avian flu?
This is an infectious viral infection of birds and less commonly pigs.
Avian or bird flu due to the H5N1 virus has spread rapidly throughout poultry flocks in Asia and more recently to Eastern Europe. It is proving difficult to eradicate in birds.
Humans are rarely affected with avian/bird flu and this has mainly happened through close contact with live infected birds or their faeces.
Does the seasonal flu vaccine protect against avian flu?
Seasonal flu vaccine doesn't protect against avian influenza and there is no vaccine currently licensed against avian influenza.
Remember
If you are over 65 or have a long term medical condition you should also ask your doctor about the pneumococcal vaccine which protects against pneumonia, if you have not previously received it.
Keep well this winter
- Eat well: eat at least one hot meal a day.
- Keep warm: wear several layers when outside and keep at least one room heated during the day.
- Keep active.
- Get vaccinated.
Where can I find out more?
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