Should I have the flu jab? How does it work?

For many, the offer of a vaccine is protection against a number of viruses.

Just like the common cold, flu is spread by coughs and sneezes, but it is caused by different viruses and is much more serious – around 600 people die every year from complications, such as bronchitis or pneumonia.

Should I have a flu jab?

The NHS offers a free flu vaccine to adults over 50 years of age, and those who are considered vulnerable to the virus and its complications each year, but just how effective is it?¹

If you’re considering having the vaccine, but unsure of the risks, we have put together the below information designed to put your mind at rest. 

Who can have a flu jab?

The NHS states that the flu vaccine is available to people who:²

• Are 50 and over (including those who'll be 50 by 31 March 2021)
• Have certain health conditions
• Are pregnant
• Are in long-stay residential care
• Receive a carer's allowance, or are the main carer for an older or disabled person who may be at risk if you get sick
• Live with someone who's at high risk from coronavirus (on the NHS shielded patient list)
• Frontline health or social care workers

When can I get a flu jab?

It’s advised that the best time to get the flu vaccine is in the autumn (late September) before the flu starts to spread, however it is possible that you get your flu jab later.

Is the flu jab safe?

NHS England states that the flu vaccination is a safe and effective method that protects you against strains of the flu virus that circulate each year.³

Hence why it’s advised that you receive one annually.

The vaccine cannot give you the flu. It also cannot protect you from COVID-19 or seasonal coughs and colds.

How does flu jab work?

Adults will usually receive the flu vaccination through an injection. Children will usually receive a nasal spray to protect them against the virus and its alternatives.

The vaccine contains inactivated extract from different variations of the flu virus. It works by supporting your immune system to produce antibodies against the flu virus.

The antibodies then stay in your body so that you're exposed to a small, natural amount of the flu.

Your immune system then recognises it, attacks it and stops it from escalating into the flu virus.

How effective is the flu jab?

According to the NHS, the flu vaccine is the best way to protect yourself against the flu. Usually, it can take 10 to 14 days for the flu vaccine to work.⁴

Flu vaccines help protect you, and others around you against the main types of flu viruses.

While there is still a chance you might get flu, this is thought to be a more mild, less fierce strain of the flu compared to other variants.

The vaccine is also meant to stop you spreading the flu to others around, including vulnerable people who may be at risk of serious problems from flu.⁵

Can you have a flu jab if you have a cold?

Minor illnesses, such as a cold will not interfere with your flu vaccine.

Mild symptoms such as a cough, headache, or a sore throat will not have any effect on your immune system’s ability to create antibodies against flu infections.

However, if you are feeling ill with a fever on the day of your injection, it is recommended that you wait until you have recovered before receiving your vaccination.⁶

This is because your immune system may be less effective if it is busy fighting off another infection rather than creating the antibodies required to fight off the flu virus.

Can you still get flu after flu jab?

Yes, the flu jab is intended as a preventative measure.

This means that it can help you to stop future infections but will not be able to prevent you from catching flu if you have an existing infection.

To put it simply, if you get the jab but you have been infected by flu – there is a chance that you can still get it.⁷

Do I need a flu jab?

To help you decide whether you would like a flu jab or not, why not take our 'should I have the flu jab’ quiz. Simply answer ‘yes’ or ‘no’ to each question, to discover whether you need the flu jab this winter.

Q1. Those in ‘high risk’ groups will be offered the flu jab by their GP. Are you:

• Aged 65 or over
• Pregnant
• Living in a residential or nursing home
• The main carer of an older or disabled person

Or do you have:

1. a heart problem
2. chest complaint or breathing difficulties
3. a kidney disease
4. lowered immunity due to disease or treatment
5. a liver disease or diabetes
6. a neurological condition such as multiple sclerosis
7. a problem with, or removal of, your spleen e.g. sickle cell disease

These people are more susceptible to the effects of flu, so vaccination reduces the risks of complications.

Q2. Are you a healthcare worker, have young children, or work with children?

Health and social care workers can get the flu jab to help protect them, their patients, colleagues and families.

Anyone working with, or who has, young children is also advised to have the jab, as young children typically get between seven and 10 colds a year.

Healthy children aged two and year 5 in school will automatically be offered the flu vaccine as a nasal spray as part of the childhood vaccination programme.

Handpicked article: Four easy ways to boost your child’s immunity

Q3. Do you meet a lot of different people every day; do you work as a shop assistant or bar tender, for example?

These people have a lot of exposure to the general public, so their risk of picking up a flu virus also increases.

At this time of year – as shops and pubs start getting busy in the run-up to Christmas – you’re also more likely to come into contact with more people than normal.

Q4. Would you be comfortable taking time off work?

If you’re self-employed, or the head of a company, your business could suffer if you’re laid low with flu.

Those worried about losing their jobs may also want to take out ‘insurance’ against getting flu and having to take time off. The flu jab can help protect your economic health too!

Q5. Are you a student, or studying for exams?

Students are much more likely to come into contact with others in crowded areas, upping their chances of catching flu.

And if you’re studying for exams, you don’t want to fall ill during exam season and miss them.

Handpicked article: How a better diet can improve exam results

Q6. Are you trying to get pregnant?

All pregnant women should have the flu jab to protect themselves and their babies.

But what if you’re planning to get pregnant over winter?

Talk to your GP about having the jab – if you do become pregnant and then get flu you may need urgent medicine if you’re not vaccinated.

Q7. Are you stressed at the moment?

If you’re under a lot of stress, you may not be eating or sleeping properly – both key to a healthy immune system.

Stress also triggers the release of steroids, which stop the body producing white blood cells that fight viruses.

Handpicked article: 6 super foods to boost your immunity

Q8. Do you seem to catch every bug going?

If you’re the sort of person who always goes down with a cold, experts say it may be worth having the jab.

Your results

Mainly ‘yes’

You should think about getting the flu vaccination.

The best time to be vaccinated is in the autumn, from October to early November, but you can still have the jab later on.

Speak to your GP or visit your local pharmacy for further information.

Mainly ‘no’

Although you may not need the flu jab, keep your immune system strong to ward off other cold-weather conditions like coughs, colds or the winter vomiting bug.

Handpicked article: How to boost your immune system naturally

Mixture of ‘yes’ and ‘no’

Still unsure if you need the jab? Visit your GP or local pharmacy to discuss it.

You can pay to have it at a pharmacy if you’re not eligible on the NHS, or your company may offer it to protect employees over winter.

Maintaining your immune system is another essential weapon in your cold weather arsenal.

Handpicked article: Everyday actions that may be hurting your immune system

Can the flu shot make you sick?

It is possible that you may feel some side effects from the flu vaccine, however, it is very safe so it's unlikely that you will feel any serious sickness.

There may be a risk of an allergic reaction to the vaccine if you have an egg allergy. This is because that some forms of the flu vaccine are made using eggs.

If this is a concern for you, we would suggest asking your GP or pharmacist for a low-egg or egg-free vaccine.

And as mentioned previously, if you are ill with a fever or high temperature, it is best to wait until you’ve fully recovered before having the vaccine.

What are the side effects of this year's flu shot?

As per the NHS, flu vaccines are very safe. Any side effects are mild and will only last for a day or so.

Side effects may include:

• A slight rise in temperature
• Muscles aches or soreness
• Sore arm where the injection went in – this is more likely in those people 65 and older.

To reduce discomfort, you can:

• Try to move your arm regularly to avoid stiffness
• Take painkillers such as paracetamol or ibuprofen

Some people, including those who are pregnant, should not take ibuprofen unless recommended by a doctor.

Last updated: 19 August 2021