What is the flu vaccine?

The flu vaccine stimulates the body to produce antibodies that will protect against infection by the flu (short for “influenza”) virus.

Flu is a respiratory infection caused by different viruses. The majority of the population overcomes flu without the need for treatment and symptoms generally clear by themselves in around a week, but sometimes complications develop. Flu may cause serious symptoms, and may possibly be fatal. The flu vaccine is a good way of minimising your own risk and the possibility of infecting other people.

The specialist can tell you about the different types of vaccine available; for example, there are vaccines specifically developed for people aged over 65 years.

Why is it done?

The main reason for flu vaccination is to protect against possible flu-related complications. There are, however, other reasons too.

It is important that people with kidney disease, diabetes, HIV infection, heart problems, or asthma are vaccinated, because flu in these populations is more likely to lead to more-serious complications such as pneumonia.

Other groups, such as children and adolescents, may develop a serious disease called Reye's syndrome if they are taking aspirin regularly.

Finally, by being vaccinated, you will protect those closest to you who might develop a serious infection, such as babies, people with serious diseases, and the elderly. The phenomenon whereby vaccinated people protect vulnerable people around them is called herd immunity.

Who should be vaccinated?

The NHS routinely provides the flu vaccine to:

• Those over the age of 65
• Those with certain medical conditions
• Children aged 2 and 3
• Children in reception and years 1, 2, 3, 4 and 5 at school
• Pregnant women

Who shouldn’t be vaccinated?

Those who have an egg allergy, as some vaccines are made using eggs – although egg-free vaccines are now available. Speak to your doctor if you are unsure.

If you have ever had a serious allergic reaction to a flu vaccine in the past, you should also speak to your doctor before receiving the vaccine.

What does it involve?

Flu vaccines stimulate the body to produce antibodies two weeks after vaccination. Antibodies provide effective protection against infection by the viruses included in the vaccine. This vaccine protects against seasonal flu; specifically, it provides protection against three types of virus:

• Flu virus type A (H1N1)
• Flu virus type A (H3N2)
• Flu virus type B

There is another type of flu vaccine that protects against four types of virus, the three mentioned above and:

• Variant of flu virus type B

Are there any side effects?

There are very rarely serious side effects from the vaccine. As the vaccine contains a small amount of the flu virus itself, you may experience mild flu symptoms such as aches and pains, and mild fever.

The flu vaccine is normally administered as a nasal spray in young children, and side effects of this may include a runny or blocked nose, a lack of appetite, and a headache. The flu vaccine, however, has been demonstrated to be safe and has a good safety record.