Skip to main content

Why do some people with a severely weakened immune system need an additional dose of the COVID-19 vaccine between October 2025 and January 2026?

COVID-19 is a very infectious respiratory disease which can cause serious illness in people who have a severely weakened immune system (severe immunosuppression). If you are an individual who has a severely weakened immune system due to an underlying health condition or medical treatment, you may not have had a good immune response to your previous doses of the COVID-19 vaccination. You are being offered an additional dose of the vaccine to improve your levels of immunity to give you better protection.

Who is considered to have a severely weakened immune system?

The vaccine is being offered to individuals aged 6 months and over who have severe immunosuppression. This includes those who had or have:

  • blood cancers (such as leukaemia or lymphoma)
  • lowered immunity due to treatment (such as high dose steroid medication, biological therapy, chemotherapy, radiotherapy)
  • lowered immunity due to inherited disorders of the immune system
  • an organ or bone marrow transplant
  • diseases and treatments that affect the immune system

If you are unsure if you require an additional dose of the vaccine between October 2025 – January 2026, speak to the specialist involved in your care or alternatively contact your GP surgery.

When will the additional dose of the COVID-19 vaccine be given?

The Autumn/winter campaign will run from Wednesday 1st October 2025 to the end of January 2026.

Ideally the vaccine will be given at least 3 months from your previous dose of the vaccine.

I’m planned to receive immunosuppressive treatment – when should I receive my vaccine?

For individuals about to receive planned immunosuppressive treatment, vaccination should take place 2 weeks before immunosuppressive treatment commences, or 2 weeks after the period of immunosuppression. Your specialist will be able to advise you on this.

If you have recently become immunosuppressed, and not previously received a COVID-19 vaccine, your specialist or GP may refer you for vaccination.

How will I get my vaccination?

You will be contacted by the Swansea Bay UHB Immunisation Team to let you know when and where you will receive your COVID-19 vaccination. Further information about when or how you will be contacted about your Autumn/Winter COVID-19 vaccination can be found by following this link.

Will I experience any side effects?

Very common side effects include:

  • having a painful, heavy feeling and tenderness in the arm where you had your injection for several days after the vaccine
  • feeling tired
  • headache
  • general aches, or mild flu like symptoms

A less common side effect is swelling of the local glands in the neck and armpit, this starts a few days after the vaccine and may last for up to two weeks.

The immuniser will advise you on how to manage potential side effects at the vaccination appointment.

Rydym yn croesawu gohebiaeth a galwadau ffôn yn y Gymraeg neu'r Saesneg. Atebir gohebiaeth Gymraeg yn y Gymraeg, ac ni fydd hyn yn arwain at oedi. Mae’r dudalen hon ar gael yn Gymraeg drwy bwyso’r botwm ar y dde ar frig y dudalen.

We welcome correspondence and telephone calls in Welsh or English. Welsh language correspondence will be replied to in Welsh, and this will not lead to a delay. This page is available in Welsh by clicking ‘Cymraeg’ at the top right of this page.