Immunisation against seasonal flu (the flu jab) is given every year to people at risk of developing serious complications from seasonal influenza (flu). People who are recommended to receive the flu jab are listed below. If you have the flu jab you greatly reduce your chance of getting seasonal flu.
Influenza (flu) is an illness caused by the flu virus. There are different strains of flu virus. Flu is passed from person to person through droplets created when someone with the infection sneezes or coughs. You can also catch it by touching a surface where the virus has been deposited. Flu can spread quickly in these ways.
Symptoms of flu include a high temperature (fever), muscle aches, cough, headache and extreme tiredness. Flu usually lasts for between two and seven days. Most people recover fully. Complications such as a chest infection or pneumonia develop sometimes.
Complications are more common in young babies, older people, people with an underlying disease (especially heart or lung diseases), pregnant women and people who have a weak immune system. Complications are sometimes serious and a number of people die each year in the UK. These are usually elderly.
There are three types of flu virus - A, B and C. Influenza types A and B cause most of the cases of flu. Each winter a different strain of the flu virus causes an outbreak which affects many people. This is called seasonal flu. During an outbreak of seasonal flu, if you get a flu-like illness, it is more likely to be caused by the prevailing flu virus than by any other. Most cases of flu usually occur in a period of six to eight weeks during the winter.
Swine flu is caused by a particular strain of influenza A virus which is called influenza virus A (H1N1v). It seems to affect children and young adults more commonly than those over the age of 60 years. Most people with this type of influenza have a mild flu-like illness. You are more likely to have sickness and/or diarrhoea with this type of flu. This type of flu virus caused the pandemic in 2009/10. It is also thought likely to be around this winter (2011/12).
Note: bird flu (avian influenza) is different and is more serious.
Flu immunisation (the flu jab) gives excellent protection against seasonal flu and lasts for one year. If 10 people have the flu jab, it will provide protection from flu for 7 or 8 of them.
The immunisation is normally given in October or November each year. It is made from the strain of flu virus that is expected in the coming winter. Each year this is slightly different, so a new jab needs to be made every year. You need a yearly jab to stay protected.
Flu jabs do not prevent other viral infections which can cause coughs, colds and flu-like illnesses. It protects only against the particular flu virus that is expected in the coming winter.
The adult immunisation does not actually contain any living flu virus. This means that it cannot cause flu or any other infections. If you develop a cough or cold shortly after having a flu immunisation it is a coincidence.
Seasonal flu is the particular type of flu virus that arrives in the UK each autumn. The actual type varies from year to year. The new jab is developed each year to protect against the expected type. This year (2011-2012), the flu jab will also provide protection against the influenza A viral H1N1v strain (swine flu). It takes up to 14 days for full protection after having the jab.
The Department of Health (DH) issues advice as to whom should be immunised. This is reviewed from time to time. The aim is to protect people who are more likely to develop complications from flu. Current advice is that you should be immunised against the seasonal flu virus each autumn if you:
In addition to the main at-risk groups of people listed above:
If you are healthy and aged under 65 and you do not fall into any of the above categories, then you do not need immunisation against seasonal flu. This is because you are unlikely to develop complications from flu.
From September 2013 all 2 year old children will be offered a nasal influenza vaccination. This will be extended to all preschool and primary school aged children from 2014. Secondary school aged children will be enrolled in pilots from 2014, which will be extended to all from 2015.
Pregnant women are at increased risk of developing a more severe illness. They are also more likely than nonpregnant women to be admitted to hospital. There are no known problems from giving seasonal flu jab to women who are pregnant.
Immunisation against the seasonal influenza virus usually causes no problems. You may have a temporary mild soreness at the injection site. Sometimes, it can cause a mild fever and slight muscle aches for a day or so. This soon settles and does not lead to flu or other problems.
Serious reactions have been reported but are rare. For example, a severe allergic reaction, inflammation of nerves and inflammation of the brain are very rare reactions.
Children will be given a different vaccine to adults. It is called Fluenz® and is given by nasal spray. It contains a live but weakened form of the flu virus. It will not cause flu in a healthy child. However, if a healthy child lives with someone who does not have a healthy immune system (for example who has HIV or has had a bone marrow transplant) they should have the other (inactive) type of vaccine. The live, weak form of vaccine has been shown to be more effective in preventing flu in children.
The vast majority of people can receive the flu immunisation. However, the following groups of people should not be immunised:
The flu immunisation can be given at the same time as other immunisation; it is often given at the same time as the pneumonia immunisation. It is also safe to be given if you are either pregnant or breast-feeding.
Their leaflet - Seasonal flu vaccination - who should have it and why