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Flu vaccine - Flu vaccine for adults

When should I get a flu vaccine?

Flu vaccines usually become available towards the end of September or the beginning of October each year. Ideally, you should have your flu vaccine before flu starts to spread, which is usually not before mid-December. You can have it later, but having it before flu starts to spread is better. Protection starts around two weeks after you have had a flu vaccine. 

If you are in a group that is at increased risk of becoming very ill if they catch flu, you should have a flu vaccination every year. 

Can the flu vaccine be given at the same time as other vaccines?

Flu vaccines can be given at the same time as most other vaccines including COVID-19 vaccines if necessary. However, COVID-19 or flu vaccinations won’t usually be given at the same time as the Respiratory Syncytial Virus (RSV) vaccine. Your healthcare professional will be able to provide further advice. 

Make sure you get your vaccines as soon as they are offered to you. 

Will I get any side effects from a flu vaccine?

Like all medicines, vaccines can cause side effects. This is because vaccines work by prompting a response in your immune system. Most side effects are mild and short-term, and not everyone gets them. 

Some of the most common side effects in the first day or two include: 

  • Pain, bruising, redness, hardness or swelling where you had the injection 
  • general aches or flu-like symptoms 
  • feeling tired 
  • loss of appetite 
  • diarrhoea 
  • headache, and 
  • a mild fever. 

You may have a mild fever for two to three days after having a vaccine. However, a high temperature is unusual and may be because you have another infection or illness. If you are worried speak to your doctor or nurse. You can take paracetamol (follow the advice in the packet and do not take more than the recommended dose) and rest to help you feel better. 

The flu vaccine will not give you flu. 

If your symptoms seem to get worse or if you are concerned, call NHS 111 or your GP surgery. If you do get advice from a doctor or nurse, make sure you tell them what vaccines you have had so they can assess you fully. 

For all side effects and for more information about the vaccine, please see the relevant patient information leaflet: 

Adults aged 65 years and over 

At-risk adults aged 60 to 64 years 

At-risk adults (including pregnant women) less than 60 years 

You should report suspected side effects of vaccines and medicines through the Yellow Card scheme. You can do this online by visiting Yellow Card’s website or by calling the Yellow Card scheme hotline on 0800 731 6789 (Monday to Friday, 9am to 5pm).

What do I need to do?

If you are an adult in a risk group, are pregnant, or are aged 65 or over, you can get your flu vaccine at your GP surgery or at some community pharmacies.  

Frontline healthcare workers should receive the flu vaccine through their employer as part of occupational health care. If you are unsure, ask your employer where to get your vaccine.  

Social workers (in contact with residents or service users), care home staff and domiciliary carers should talk to their manager about getting the flu vaccine. 

In some areas in Wales, the vaccine may be given in some community pharmacies.  

If you think you might have missed the invitation for a flu vaccine, contact your GP or your community pharmacy. 

If your child is eligible for a flu vaccine, please see the information in the ‘Children and young people’ section further down the page.  

Can I still get flu when I am vaccinated?

Vaccination is one of the most effective ways to prevent severe illness from flu. No vaccine is 100% effective, so it is still important to know the signs and symptoms of flu, even if you or your child are vaccinated.   

For more information about flu visit the NHS 111 Wales website.

How will I know if I have flu?

When people get flu, they tend to become ill quite quickly. Symptoms can include fever, chills, a headache and aching muscles, often with a cough and sore throat. 

Around half of people infected with flu don’t even realise it, yet they can still spread the virus to others. This can sometimes cause serious illness leading to hospital care, and in rare cases, death.  

Some COVID-19 symptoms are similar to flu so please check the latest advice and follow the current COVID-19 guidance available on the Welsh government website.

What should I do if I think I have flu?

If you have a temperature or a cough, follow the current guidance available on the Welsh government website.

Flu is usually managed by resting at home, keeping warm and drinking plenty of water. You can take paracetamol (follow the advice in the packet and do not take more than the recommended dose), to lower a high temperature and relieve aches if necessary. 

However, if you are in a high-risk group you should speak to your GP surgery or community pharmacy straight away if you think you might have flu, as they may recommend a course of antiviral medicines. 

To help stop flu and other viruses spreading, remember to: 

CATCH IT 
Use a tissue when you sneeze or cough. 

BIN IT 
Put the tissue in the bin as soon as possible. 

KILL IT 
Wash your hands or use hand sanitiser. 

Page last reviewed: 18th February 2026