Confused about the flu vaccination? We’re here to separate fact from fiction

Wondering if the flu jab will give you flu? Or if it will protect you from flu for life? We shed some light on 10 myths about the flu vaccination. Plus, learn more about how to book your flu jab appointment with Boots.

What is flu?

Short for influenza, the flu virus is a respiratory (breathing) illness that causes an infection in the nose, throat and sometimes the lungs.

It can be spread easily when a person with flu coughs or sneezes and releases tiny droplets of the virus into the air. These droplets can be breathed in by others and the virus can live on hands and surfaces for 24 hours.

Flu often gets better on its own. Here, you can learn more about common symptoms and how to treat flu.

Occasionally, flu can cause some people to become seriously ill. You should ask for an urgent GP appointment or get help from NHS 111 if your baby or child has symptoms of flu and you’re concerned about their symptoms.

You should also ask for an urgent GP appointment or get help from NHS 111 if you have flu and:

• You're 65 or over
• You're pregnant
• You have a long-term medical condition such as diabetes or a condition that affects your heart, lungs, kidneys, brain or nerves
• You have a weakened immune system such as if you have HIV or are undergoing chemotherapy

• Your symptoms don’t get better after seven days

You should call 999 or go to your nearest A&E (accident and emergency) department if:

• You get sudden chest pain

• You have difficulty breathing

• You start coughing up a lot of blood

What is the flu vaccination?

The flu vaccination (also known as the flu jab) is available every year to help prevent people from catching flu and passing it on to others. It’s usually given in the autumn or early winter before the flu virus starts spreading during winter flu season. Though it is possible to have the vaccination later, and it's also important to note that flu can be caught at any time of year, not just in winter.

Certain groups of people are eligible to have the flu jab for free on the NHS, or it’s available privately. You can learn more in our article on flu vaccination FAQs.

10 myths about the flu vaccination

There’s a lot of information out there about the flu vaccination, and not all of it is true. Let’s delve further into 10 myths…

1. The flu vaccination can cause severe side effects

As with any vaccination, some side effects can occur, but most are mild and only last for a few days at most. Side effects of the flu jab can include:

• A slightly raised temperature

• Aching muscles

• A sore arm where you had the jab (more common with the vaccination given to people aged 65+)

Although possible, it’s very rare for someone to experience a serious allergic reaction to the flu jab. If this does happen, it’s usually within minutes of the vaccination being given and, rest assured, medical professionals are trained to deal with reactions and treat them immediately.

2. The flu vaccination will give me flu

Contrary to popular belief, the adult flu jab doesn’t actually contain a live version of the flu virus, meaning it’s not possible to catch flu from having the vaccination. The nasal spray flu vaccination, recommended for children, does contain small amounts of weakened flu viruses, however they do not cause flu in children.

Although some people may experience side effects including a raised temperature and aching muscles (which can also be symptoms of flu) this is usually the body’s way of responding to the vaccination.

It’s still possible to catch flu even after having the vaccination (which we explain more about in the next section). Plus, it can take 10 to 14 days for the flu jab to work. So, if you do experience flu shortly after having your jab, it’s likely you have come into contact with the virus before or just after having the jab.

3. You can still get flu after a vaccination, so it doesn’t work

It’s true that you can still catch flu even after having the flu jab, but this is because no vaccination is 100% effective.

The flu jab is designed to help reduce your risk of catching the main types of flu virus and spreading flu to others. If you do catch it after having your vaccination and enough time has passed for the vaccination to work, then it’s likely that your symptoms may be milder and not last as long because the flu jab will have given your body some level of protection against the virus.

4. If you’re pregnant you shouldn’t get the flu vaccination

On the contrary, it’s actually recommended to get the flu vaccination when pregnant. This is because studies have shown that having flu whilst pregnant may increase your risk of serious complications, particularly in the later stages of pregnancy.

If you have flu during pregnancy, it could also cause complications for your baby, which can be fatal in some cases.

The flu vaccination is offered for free on the NHS to those who are pregnant, and it can be given at any stage of pregnancy. Some protection from flu is also passed on to your baby for the first few months of their lives.

5. Once I have the flu vaccination, I’m protected for life

Having the flu vaccination won’t offer protection against flu for life. There are different strains of the influenza virus that are constantly adapting and changing. The flu vaccination is updated every year to offer the best protection against the strains of flu that are expected to be circulating that year, so it’s recommended to have the flu jab annually.

6. The flu vaccination contains mercury

Some vaccinations in the past or in certain countries have contained a mercury-based preservative called thiomersal (also known as thimerosal). Whilst this has been approved for use in vaccinations by the World Health Organisation and is not the same as the toxic mercury that can build up in the food chain, thiomersal is not present in vaccinations routinely used in the UK.

7. Flu is just a heavy cold, so I don’t need a vaccination

Whilst flu shares many symptoms of a cold, they’re not the same.

Colds usually:

• Come on gradually

• Mainly affect your nose and throat

• Make you feel unwell, but you can still carry on with day-to-day activities

Flu usually:

• Comes on suddenly, within a few hours

• Affects more than just your nose and throat

• Makes you feel unwell and exhausted, meaning you can’t carry on with day-to-day activities

Flu is usually more severe than a cold and, for some people, can cause serious illness.

Some of the most common signs and symptoms of flu include:

• Sudden fever (high temperature over 38°C)

• Achiness

• Tiredness or feeling exhausted

• Dry cough

• Sore throat


Here, you can learn more about telling the difference between a cold and flu.

8. Flu isn’t serious, so I don’t need a vaccination

For some people, flu will go away on its own and will only cause unpleasant symptoms that can be managed by resting and staying hydrated. You may also want to consider an over-the-counter medication (if needed and if suitable for you). For others, however, flu can cause serious complications that may need hospital treatment and can be life threatening in some cases.

Those more at risk of serious illness from flu, include:

• Older people

• Very young people

• Those who are pregnant

• Those with a long-term medical condition, such as ones that affect your heart or respiratory (breathing) system

• Those with a weakened immune system, for example people with HIV or those having certain medical treatments

The vaccination is the best way to help protect against flu. Even if you’re not at high risk of complications, getting vaccinated can help stop you from catching flu and passing it on to someone who is more at risk than you.

9. Healthy people don’t need the flu vaccination

Although flu is usually not serious for many people, it's still likely to make you feel too tired or unwell to carry on with normal activities. So, getting the vaccination can help reduce your risk of missing important commitments because of the virus.

Even if you’re otherwise healthy or don’t fall into the higher-risk groups of people, it’s still possible to fall seriously ill from flu in some cases. The virus affects everyone differently, so otherwise healthy people should still consider the annual flu vaccination.

It can also help protect you from catching flu and then passing it on to people who are at a higher risk of complications from flu than you. This is particularly important if you care for, live with or work with those in a higher-risk group.

10. I can’t spread flu if I have no symptoms

You can actually spread flu from one day before your symptoms begin, meaning you can be contagious without knowing you have the virus. It can usually be spread until around five to seven days after your symptoms started, though, children and people with a weakened immune system may be contagious for longer.

It’s also possible to have flu without experiencing any symptoms, but you may still be able to spread the virus to other people in the usual way by coughing and sneezing droplets of the virus into the air and onto surfaces.

How to book a flu vaccination appointment

Certain groups of people are eligible to have a flu vaccination each year for free on the NHS. People who are eligible may include:

• Those aged 65 and over

• Those with certain health conditions

• Those who are pregnant

• Those in long-stay residential care

• Carers who 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

• Those who live with someone with a weakened immune system, such as someone with HIV, those who have had a transplant or are having certain medical treatments for cancer, lupus or rheumatoid arthritis

The eligible groups for a free flu jab vary in each country and may be updated during the winter flu season, so please refer to local guidance.

Frontline health and social care workers may be eligible to get a flu vaccination for free from their employer.

If you’re eligible for the free NHS flu vaccination, you may be able to get this from your GP surgery or some maternity units if you’re pregnant. Alternatively, we offer the NHS flu vaccination to eligible groups aged 18+ through our Winter Flu Jab Service at most of our Boots stores in England and Wales.*

If you’re not eligible for a free NHS flu vaccination, it’s available privately through our Winter Flu Jab Service for customers aged 16+ in most Boots pharmacies across the UK, and in selected stores for children aged 11 to 15.**