Is It Too Late to Have the Flu Jab? What an Early Flu Season in Wales Means

Find out about flu vaccination

If you’ve seen the headlines about flu arriving early in Wales and wondered, is it too late to have the flu jab?, the short answer is no. This guide is for adults and families in Cardiff, St Mellons and the surrounding area who haven’t been vaccinated yet.

We cover what an early start means, how long protection takes to build, who can get a free NHS vaccine, the usual side effects and who should check with a pharmacist or GP first.

On this page

Is It Too Late to Have the Flu Jab This Winter?

No. Public Health Wales has said that although flu season has started early, there is still time to get your vaccine before flu reaches its peak. Its message is that eligible people should get vaccinated as soon as possible.

The NHS Wales programme for adults is also scheduled to run until 28 February 2027. So if you’ve put it off, you haven’t missed the window.

That said, sooner is better than later. Flu can be unpleasant for anyone and serious for some people, and the vaccine needs a little time to work. If you’re asking yourself whether it’s too late to have a flu jab, the most useful thing you can do is book it this week rather than wait.

What an Early Start to Flu Season Means in Wales

Flu season in Wales usually begins around late November or early December. Public Health Wales announced on 6 November 2026 that this year’s has begun earlier than that, although not as early as last year’s.

Here’s what we know so far:

  • Levels are still low, but expected to rise. Public Health Wales says case numbers are expected to climb over the coming weeks.
  • Two types of flu A are circulating. These are influenza A(H1) and A(H3), with more A(H1) cases confirmed so far.
  • Different groups can be affected. Public Health Wales has said A(H1) can have a greater impact on younger people, including children, pregnant women and those with underlying health conditions, while A(H3) has historically affected older adults more.

Hospital figures are also edging up. Welsh Government data reported in the press showed 46 people with confirmed flu admitted in the week to 1 November, up from 32 the week before. Projections suggested admissions would stay stable in Cardiff and Vale over the following fortnight, but that’s a short-term forecast and things can change quickly.

A Note on How Well the Vaccine Matches

The UK Health Security Agency has said that the A(H1N1) strain has drifted from the version used in this season’s vaccine, and that it’s too early to know how that will affect how well it works. Flu viruses change every year, and no vaccine gives complete protection. Even so, if you do catch flu after vaccination, it’s likely to be milder.

How Long Does the Flu Jab Take to Work?

Your body needs time to build up protection after the vaccine. NHS guidance generally puts this at about two weeks for the immune response to fully develop.

In practice, that means:

  • You can still catch flu in the days after your jab, because protection isn’t complete yet.
  • The earlier you’re vaccinated, the sooner you’re covered as flu becomes more common.
  • Getting the jab now still makes sense. Flu activity is expected to keep rising, and there are usually several weeks of winter to come.

Feeling a bit achy after the jab doesn’t mean it has given you flu. The injected vaccine used for adults cannot give you flu. If you get flu symptoms soon after vaccination, you were most likely exposed to the virus before your body had built up protection, or you have another winter bug.

In the meantime, the usual habits still help: washing your hands, using tissues and binning them, and staying home if you’re unwell.

Who Can Get a Free NHS Flu Jab in Wales?

The NHS Wales programme for 2026 to 2027 offers a free vaccine to people at higher risk from flu, and to some others. The Welsh Government eligibility list includes:

  • people aged 65 and over (your age on 31 March 2027)
  • people aged 6 months to 64 years in a clinical risk group, such as long-term heart, lung, kidney or liver disease, diabetes or a weakened immune system
  • pregnant women
  • carers, and household contacts of people with a weakened immune system
  • health and social care workers and NHS Trust staff
  • children aged 2 and 3 years on 31 August 2026, and school-aged children from reception to year 11
  • people experiencing homelessness, and adult residents in Welsh prisons

The list is detailed, so it’s worth checking the full criteria, particularly for the definition of a clinical risk group.

How to Check If You’re Eligible

  1. Look at the Welsh Government flu vaccination page or the NHS Wales vaccine information.
  2. Check whether your GP surgery has sent you an invitation.
  3. Ask one of our pharmacists. If you’re unsure, we can talk through your circumstances and point you to the right place.

Children’s vaccines mostly run through different routes. Most school-aged children are offered theirs through the school immunisation service, and eligible 2 and 3 year olds usually get a nasal spray through their GP surgery.

If you’re not eligible for the NHS vaccine, you can still choose to have a flu jab privately. Many people do this for work, for travel, or because they live with someone vulnerable.

Flu Jab Side Effects and Who Should Check First

Like all vaccines, the flu jab can cause side effects, but most are mild. The most common ones in adults get better within 1 to 2 days. They include:

  • a sore, red or swollen arm where the injection went in
  • a slightly raised temperature
  • aching muscles, a headache or feeling tired

Serious allergic reactions are very rare, which is one reason you’re asked to wait briefly after vaccination. These are much less serious than flu itself, but if you feel very unwell after your jab, seek medical advice.

Speak to a Pharmacist or GP First If You…

  • have ever had a severe allergic reaction (anaphylaxis) to a previous flu vaccine or any of its ingredients. This is the main reason someone can’t have the vaccine.
  • have a severe egg allergy. Different vaccine types are available, so check which is suitable for you.
  • have a high temperature or feel acutely unwell. Vaccination may be delayed until you’re better, though a minor cold is not usually a reason to wait.
  • have a weakened immune system or are pregnant, and aren’t sure what’s right for you.
  • are asking about a child. Children’s vaccines differ from adults’, including the nasal spray, so please ask us or your GP.

If you think you may already have flu, don’t come into the pharmacy for a jab. Call us first, or use NHS 111 Wales for advice.

Why Choose Wellness Pharmacy for Your Flu Jab in Cardiff?

We’re your local independent pharmacy on Newport Road in Old St Mellons, and we’ve been helping families across east Cardiff stay well through the winter. If you’ve been wondering whether it’s too late to get your flu jab, come and have a chat with us.

  • Flu vaccinations for eligible patients on the NHS, free of charge if you qualify under the NHS Wales programme.
  • Private flu vaccinations for anyone who isn’t eligible but would like protection.
  • Pharmacist-led advice on eligibility, allergies, side effects and whether the vaccine is right for you.
  • Friendly, local and easy to reach, with no need to travel into the city centre.

Book online or pop in to see our team, and we’ll get you sorted.

Book now for a consultation with our pharmacists

Frequently Asked Questions

Is it too late to get a flu jab in the UK if flu has already started?

No. Public Health Wales has said there is still time to be vaccinated before flu peaks, and the NHS Wales adult programme runs until the end of February 2027. Protection takes around two weeks to build, so it’s best to have it as soon as you can. Even if you catch flu afterwards, it’s likely to be milder.

What are the possible side effects of the flu jab?

Most people have none or only mild ones, such as a sore or swollen arm, a slightly raised temperature, aching muscles, a headache or tiredness. These usually pass within a day or two. Serious allergic reactions are very rare. If you’ve ever had a severe reaction to a vaccine, tell the person vaccinating you beforehand.

What is influenza?

Influenza, or flu, is a viral infection of the nose, throat and lungs that spreads easily, especially in winter. It’s different from a cold: symptoms often come on suddenly and can include fever, aching body, tiredness and a dry cough. Most healthy people recover at home, but flu can cause serious illness in older adults, pregnant women, young children and people with long-term conditions.

What is the minimum age to get the flu jab in the UK?

On the NHS in Wales, children can be vaccinated from 6 months old if they are in a clinical risk group. Children aged 2 and 3 and school-aged children are offered the vaccine as part of the childhood programme, usually as a nasal spray. For anything beyond this, ask your GP or a pharmacist, as the right vaccine depends on age and health.

Is it better to have a flu jab in the morning or afternoon?

There’s no need to worry about the time of day. The best time to have your flu jab is the first appointment you can get. Wear short sleeves or a loose top so the vaccinator can reach your upper arm easily.

Medical Disclaimer

This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your GP, pharmacist, or qualified healthcare professional before starting, stopping, or changing any treatment. A qualified prescriber must assess individual clinical suitability. Wellness Pharmacy only supplies prescription treatments following a full clinical assessment.

Thomas HarriesWritten byThomas HarriesPrescribing Pharmacist and OwnerView full clinician profile →

Further reading

Written by (Prescribing Pharmacist and Owner).