A Guide to having a seasonal flu jab for protection from influenza, a
highly infectious respiratory illness caused by a flu virus.
If you are elderly or have a long term impairment or disability you should seriously consider
having a flu jab as catching the virus could make you seriously ill.
The flu virus spreads rapidly through the coughs and sneezes of infected people.
Seasonal flu immunisation, or the flu jab, is the injection of a vaccine against flu. It gives good protection from flu that lasts for one year.
The flu jab is offered to people in at-risk groups, who are at greater risk of developing serious complications from flu. To stay protected, they need to have it every year.
The vaccine, which is normally available in the autumn, is made from the strains of flu that are expected in winter.
How effective is it?
The flu vaccines currently available give 70-80% protection against infection, with flu virus strains closely matching those in the vaccine.
In the elderly, protection against infection may be less, but immunisation reduces the chances of pneumonia, hospital admissions and death from seasonal flu.
Who should have the seasonal flu jab?
For most people, seasonal flu is unpleasant but not serious and they recover within a week.
However, certain people are at greater risk of developing serious complications of flu, such as bronchitis and pneumonia. These may require hospital treatment. A large number of elderly people die from flu every winter.
The seasonal flu vaccine is offered free of charge to these at-risk groups to protect them from catching flu and developing these complications.
Also, this winter, the seasonal flu vaccine will be offered to pregnant women not in the high-risk groups who have not previously been vaccinated against H1N1 (swine) flu.
It is recommended you have a flu jab if you:
- are 65 or over,
- have a serious medical condition ,
- live in a residential or nursing home,
- are the main carer for an elderly or disabled person whose welfare may be at risk if you fall ill,
- are a healthcare or social care professional directly involved in patient care, or
- work with poultry (see below).
Also, this year, it is recommended that pregnant women not in the high-risk groups who have not previously been vaccinated against H1N1 (swine) flu have the seasonal flu jab.
If you are the parent of a child (over six months) with a long-term condition, speak to your GP about the flu jab. Your child's condition may get worse if they catch flu.
If you are the carer of an elderly or disabled person, make sure they have had their flu jab.
You are entitled to a free flu vaccination if you work in close contact with poultry. This includes people who:
- work in areas where poultry are kept for rearing or egg production,
- handle or catch live poultry,
- sort eggs in poultry houses, or
- slaughter or clean poultry.
Free flu vaccination is offered to poultry workers because they are at slightly greater risk of catching bird flu if there is an outbreak.
If the bird flu and human flu viruses were to mix, a new flu virus could be made. A flu vaccination protects against human flu, reducing the risk of the viruses mixing even if a person had both human flu and bird flu at the same time.
The flu vaccine is being offered as a precautionary measure to eliminate this slight risk. There is currently not an increased risk of a bird flu outbreak in the UK and this risk remains low.
Getting your seasonal flu vaccination
If you think you need a seasonal flu vaccination (see Who should have it), check with your doctor, nurse or local pharmacist.
Most GP surgeries organise special vaccination sessions in the autumn.
The flu virus circulates every winter, usually over a period of a few weeks. The best time to have a flu jab is in the autumn, between late September and early November. Do not wait until the winter, when there is already a flu epidemic.
About the seasonal flu vaccine
Types of flu
There are three main types of flu:
- Type A occurs every two to three years and is more serious than type B. The virus is likely to mutate to a different version, to which populations have no resistance.
- Type B generally causes a less severe illness and is responsible for smaller outbreaks. Flu B mainly affects young children (aged five to 14).
- Type C usually causes a mild illness similar to the common cold.
Typically, every year one or two strains of type A flu may be circulating, as well as a type B strain.
How the vaccine is made
The seasonal flu vaccine contains different types of flu virus, which are grown in hens' eggs.
They are then inactivated (killed) and purified before being made into the vaccine.
There are currently three types of vaccine that are as effective as each other but made in different ways:
- The first type is made by inactivating whole viruses with organic solvents or detergents ('disrupted live' vaccines).
- The second type is made by extracting and purifying components of the flu viruses ('surface antigen' vaccines).
- The third type uses virosomes, which are the empty envelopes of flu viruses that lack the genetic material of the original virus.
Because the flu virus is continually changing and different types circulate each winter, a new flu vaccine has to be produced each year.
How the flu vaccine composition is decided
The World Health Organization (WHO) decides each February which three flu viruses are likely to be the greatest threat that year.
The decision is made by analysing several thousand flu viruses in the WHO flu laboratories around the world. These laboratories assess which strain has been dominant over the previous winter and look for evidence of new strains that have the potential to spread, and how well the current vaccine protects against them.
Production of the vaccine starts in March each year after the WHO announcement. It is available in the UK from September onwards.
How it protects you
About a week to 10 days after you have had the flu injection, your body starts making antibodies to the virus in the vaccine.
Antibodies are proteins that recognise and fight off germs that have invaded your blood, such as viruses. They help protect you against any similar viruses you then come into contact with.
The flu virus changes every year, so you need to have a flu jab annually to make sure that you are protected against the latest strain of the virus.
Who should not have the seasonal flu jab?
You should not have the seasonal flu vaccine if:
- you have had a previous allergic reaction to a flu vaccine (rare), or
- you have a serious allergy to hens' eggs (very rare), because the vaccine is prepared in hens' eggs.
Generally, if you are healthy, under 65 and do not fall into any of the at-risk groups, it is not necessary for you to have a flu jab as your body can fight off the virus if you become ill with it.
If you are ill with a fever, do not have your flu jab until you have recovered.
If you are pregnant, talk to your GP about having the vaccination. No problems have been reported in pregnant women who have had the flu jab.
Frequently asked questions
When am I most at risk from flu?
Influenza reappears every winter, usually over a short period of a few weeks, so that a lot of people get ill around the same time. In a bad year, this can amount to an epidemic, but it is impossible to predict how much flu there will be every year.
Does everyone need a flu jab?
Ask your GP about having a flu vaccination if you:
- are 65 or over
- have a serious medical condition
- live in a residential or nursing home
- are the main carer for an elderly or disabled person whose welfare may be at risk if you fall ill
- are a healthcare or social care professional directly involved in patient care
- work with poultry
You may also need the flu jab if you are pregnant. For more information, see Who should have it.
Why are certain groups targeted for the flu jab?
Complications such as bronchitis and pneumonia are more common in those with underlying diseases such as those mentioned above, especially if they are also elderly, and related flu deaths are almost entirely in these groups.
In long-stay residential accommodation, influenza vaccination prevents the rapid spread of infection that causes outbreaks.
Can a GP vaccinate anyone else?
The final decision as to who should be offered vaccination is a matter for the patient's medical practitioner, based on the individual's medical history.
How long will the jab protect me for?
The flu jab will protect you for about a year.
If I had the flu jab last year, do I need it again now?
Yes. The viruses that cause flu change every year, which means the flu (and the vaccine) this winter will be different from last winter's.
Can the flu jab actually cause flu?
No. The vaccine does not contain any live virus, so it cannot cause flu. Some people get a slight temperature and aching muscles for a couple of days afterwards and your arm may feel a bit sore where you were injected, but that is all. Any other reactions are rare; flu jabs are very safe.
When is the best time to get my flu jab?
The best time is between late September and early November, ready for the winter. You should not wait until there is a flu epidemic.
Is there anyone who cannot receive a flu jab?
There are very few people who cannot receive an influenza vaccine. The vaccines should not be given to those who have had a confirmed anaphylactic reaction (serious allergic reaction) to a previous dose of the vaccine or any component of the vaccine (including neomycin, kanamycin and gentamicin - antibiotics that may be present in tiny amounts).
The vaccines are prepared in hens' eggs and should not be given to individuals with a known allergic reaction to egg products.
If a person is ill with a fever, the vaccination should be delayed until they have recovered.
Can people get the flu vaccine privately?
If people outside the recommended groups wish to make arrangements to pay for a flu vaccination privately, that is their choice.
Why is it recommended that healthcare workers are vaccinated?
It not only prevents healthcare workers passing on flu to their patients, but should also help the NHS maintain staffing levels during a flu epidemic, when both GPs and other health services are particularly busy.
Can I get a flu jab if I'm breastfeeding?
Yes, there is no evidence of risk from vaccinating pregnant women or those who are breastfeeding.
I am allergic to penicillin. Can I still have the flu jab?
Yes, you can safely have the flu jab if you are allergic to penicillin.