Immunisation against seasonal flu
Flu immunisation (the flu jab) gives protection against seasonal flu and lasts for one year. If 10 people have the flu jab, it usually provides protection from flu for 7 or 8 of them. If the vaccine does not match the predicted flu types around that year, the protection rate can be lower. For example, in winter 2015/2016 the vaccine protected between 5-6 elderly people out of 10.
The immunisation is normally given in October or November each year. The flu injection is made from the three strains of flu virus that are most likely to cause outbreaks in the coming winter. Each year these are slightly different, so a new jab needs to be made every year. You need a yearly jab to stay protected.
The World Health Organization (WHO) monitors influenza viruses throughout the world and recommends which strains are to be included in the current year's vaccine. For the 2017/18 flu season in the UK it is recommended that vaccines contain the following three strains:
- An A/Michigan/45/2015 (H1N1)pdm09-like virus.
- An A/Hong Kong/4801/2014 (H3N2)-like virus.
- A B/Brisbane/60/2008-like virus.
Vaccines containing four strains (quadrivalent) should contain the above three viruses and a B/Phuket/3073/2013-like virus.
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.
Who should be immunised against the seasonal flu virus?
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. The flu jab takes up to 14 days for full protection after having the jab.
The Department of Health issues advice as to who 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:
- Are aged 65 or over.
- Have any ongoing (chronic) lung diseases.
Examples include chronic bronchitis, emphysema, cystic fibrosis and severe asthma (needing regular steroid inhalers or tablets). It is also recommended for any child who has previously been admitted to hospital with a chest infection.
- Have a chronic heart disease.
Examples include angina, heart failure or if you have ever had a heart attack.
- Have a serious kidney disease.
Examples include nephrotic syndrome, chronic kidney disease, a kidney transplant.
- Have a serious liver disease such as cirrhosis.
- Have diabetes.
- Have a poor immune system.
Examples include if you are receiving chemotherapy or steroid treatment (for more than a month), if you have HIV/AIDS or if you have had your spleen removed.
- Have certain serious diseases of the nervous system such as multiple sclerosis or have had a stroke in the past.
- Live in a nursing home or other long-stay residential care accommodation.
In addition to the main at-risk groups of people listed above:
- You should be immunised if you are the main carer for an elderly or disabled person whose welfare may be at risk if you fall ill with flu.
- Staff involved in direct patient care (including nursing and care homes) may be offered a flu jab by their employer.
- Pregnant women. Even if you are otherwise healthy it is now recommended that all pregnant women receive the flu jab.
If you are healthy and an adult aged under 65 years 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.
Healthy children and the flu jab
Healthy children are offered immunisation through a nasal spray, rather than an injection. Immunising your child will protect them but also cut the risk of them passing on the infection to other vulnerable members of the family.
This year (2017/18) the flu vaccine will be offered to all children who are aged 2-8 years (but not 9 years or older) on 31 August 2017. It will also be offered to all primary school-aged children living in areas where their primary school was a pilot for the vaccine programme. This is in addition to any children (from 6 months of age) who are in high-risk groups for catching flu, because of their health condition.
You may notice that this is different from last year in two ways:
Reception Year children (aged 4-5 years) will now be offered flu vaccination in their reception class, rather than at their general practice surgery.
Children in School Year 4 (aged 8-9 years) will be included in the programme this year as part of the phased roll-out of the children’s programme.
Pregnant women and the flu jab
Pregnant women are at increased risk of developing a more severe illness. They are also more likely than non-pregnant women to be admitted to hospital. Having flu when you are pregnant may also be associated with serious pregnancy problems, prematurity and lower birth weight for the baby. Your GP (or possibly midwife) should offer you a flu vaccination during your pregnancy, if it runs over the winter. If they don't, do ask for one.
There are no known problems from giving the seasonal flu jab to women who are pregnant.
Seasonal flu jab side-effects
Immunisation against seasonal influenza (the flu jab) usually causes no problems. You may have a temporary mild soreness at the injection site. Sometimes, it can cause a mild raised temperature (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 (encephalitis) are very rare reactions.
Children are given the vaccine (Fluenz Tetra®) 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.
Who should not have the seasonal flu jab?
The vast majority of people can receive flu immunisation (the flu jab). However, the following groups of people should not be immunised with the usual vaccine:
- Those who have a severe allergy to eggs. However, you can still receive a different immunisation that protects against the swine flu strain (H1N1v). There is also egg-free vaccine - see below.
- Those who have had a previous allergic reaction to a flu virus immunisation in the past.
Although most flu vaccines are grown in hens' eggs, an egg-free vaccine is available and can be given. People with a history of severe egg allergy can be given the egg-free vaccine.
Children who do not have a good working immune system should not be given the live flu vaccine. This includes children with leukaemia or HIV. Children who live with, or have close contact with, someone who has a poorly working immune system should also not be given the live vaccine. However, children who do not have a good working immune system and children who live with, or have close contact with, someone who has a poorly working immune system can be given the inactivated vaccine.
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.
Where can I have the flu jab?
You can be given your flu jab from one of the following:
- Your GP surgery.
- Your local pharmacy (if they offer this service).
- Your midwife (if they offer it for pregnant women).
Note: If you have the vaccination somewhere other than your GP surgery, they should notify your GP on your behalf.
Further reading and references
HPA guidance on use of antiviral agents for the treatment and prophylaxis of influenza 2011-12; Health Protection Agency (December 2011 - Reviewed October 2012) (archived content)
Jones JT et al; Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children (Review), The Cochrane Collaboration, 2013
Seasonal influenza: guidance, data and analysis; Public Health England
Influenza: the Green Book, Chapter 19; Public Health England (August 2015)
I believe I have the influenza B strain. Had it about ten days now.Although the cold-type symptoms are nearly gone, the worst part is how utterly fatigued I am. It feels like one step forward, one...chalkey79
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