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FAQs on the vaccine for the immunosuppressed

Information regarding the 3rd dose and booster vaccine for people who are severely immunosuppressed

Please read the FAQs below:

What is a 3rd dose of the primary course?

The Joint Committee on Vaccinations and Immunisation (JCVI)  issued guidance on the 3rd September recommending a 3rd dose of the COVID-19 vaccine as part of the primary course of vaccination. This is being  offered as a routine part of vaccination to people who are severely immunosuppressed (as defined within the JCVI guidance) due to treatment for conditions such as cancer or for those with long-term chronic conditions where their immunity is affected by medication.


Why is it recommended?

People who have a severely weakened immune system as a result of treatment, may not have the same immune response to the vaccine, and therefore, the JCVI recommends that a 3rd dose will help reduce the risk of getting seriously ill or dying from COVID-19, and from spreading COVID-19 (Coronavirus (COVID-19) vaccines


Who is eligible for it?

JCVI guidance recommends that a 3rd dose is  offered to individuals aged 12 years and over with severe immunosuppression, including those who are being treated for conditions such as cancer or for those with long-term chronic conditions where their immunity is significantly affected by regular medication. Severe immunosuppression is defined within the advice section of the JCVI guidance.

Guidance for household contacts of those who are immunosuppressed has not changed. They are recommended to be vaccinated with their first and second doses, in line with current JCVI guidance.  Details are available here.


Is there a list of conditions and treatments available which identifies people who are considered severely immunosuppressed?

The list has been published by the JCVI and is available here.


How will patients know if they are eligible?

Consultants and GPs have been asked to identify patients eligible for a 3rd dose. Patients will be contacted by their consultant / hospital doctor or GP team who will discuss the timing of the 3rd dose, in light of the current or planned immunosuppressive therapies the patient is undergoing. 

If the hospital consultant works at a hospital hub, with available vaccine supply, they should invite eligible individuals to be vaccinated on site.  If the patient cannot be vaccinated at the hospital site, the consultant will write to the patient’s GP with clear advice on timing of a 3rd dose and identifying any interaction with their current treatment. Patients should then be invited to be vaccinated at a PCN-led vaccination site.

GP teams should also identify patients on their list and liaise with hospital doctors to invite eligible individuals via their consultant. Patients will be given a clinical authorisation letter which they will need to take with them to receive their vaccination.


Can patients be vaccinated at a walk-in vaccination site?

A clinical authorisation letter will be given to eligible patients and this will act as authorisation to a COVID vaccination site that the patient requires a 3rd dose of the COVID-19 vaccine. Individuals can go to a centre which their clinician has highlighted or, if not specified, to any COVID vaccine centre offering walk-in vaccinations. Patients can find a walk-in COVID vaccine centre here: Search - Find a walk-in coronavirus (COVID-19) vaccination site ( They do not need to call their GP surgery or contact the hospital about this.


Can patients self-identify as severely immunosuppressed?

If individuals think they are eligible for a 3rd dose and have not been contacted as yet, they are advised to speak to their GP or Consultant.


Is the 3rd dose the same as the booster vaccine?

No.  The 3rd dose is not the booster vaccine.  It is recommended that the 3rd dose should be given at least 8 weeks after the 2nd dose and is part of the primary course of immunisation.  A booster jab is also expected be offered 6 months after the 3rd dose but we are currently awaiting JCVI guidance on this.


Which vaccine will be offered as a 3rd dose?

JCVI have advised a preference for mRNA vaccines (full dose Pfizer-BioNTech or Moderna) for the third dose, with the option of the AstraZeneca Vaxzevria vaccine for individuals who have received this vaccine previously where this would facilitate delivery. For those aged 12 to 17, the Pfizer-BioNTech vaccine is preferred.


When will a 3rd dose be offered? What interval will there be between 2nd and 3rd dose?

The JCVI recommends that the 3rd dose should be offered at least 8 weeks after the 2nd dose.

Research shows that, as with the interval between the 1st and 2nd dose, 8 weeks has been observed as providing the individual with the most benefits in terms of an immune response. If, however, the patient’s GP or Consultant believes that an alternative interval should be offered, because of ongoing treatment or starting treatment which will suppress the individual’s immune system, then this timing may be altered. Intervals will be considered, in light of the individual’s specific health circumstances and an assessment made by their clinician.

Where possible, JCVI recommends that the 3rd primary dose should be delayed until two weeks after the period of immunosuppression, in addition to the time period for clearance of the therapeutic agent.


Will a booster vaccine also be given?

If you have a weakened immune system and have had a 3rd dose of the vaccine, you can get a booster dose from 3 months after your 3rd dose.

Your GP or hospital specialist will invite you for your booster dose when it's due.

If you have a letter from your GP or hospital specialist inviting you for your 3rd dose, you can get your booster at a walk-in COVID-19 vaccination site. You'll need to bring your letter with you


If a severely immunosuppressed individual has had a good immune response to the first two doses, will they still be offered a third dose?

Some people who are immunosuppressed may not generate a good immune response regardless of the number of vaccine doses administrated. However, data is not currently available to reliably identify who might, or might not, benefit from a third primary dose of a COVID-19 vaccine.

The JCVI guidance highlights published studies describing the effect of a third dose of mRNA vaccine in persons who are immunosuppressed reporting increased immune responses in varying proportions.

JCVI guidance recommends that a 3rd dose will be offered to individuals aged 12 years and over with severe immunosuppression (as defined within the JCVI guidance).


What are the side-effects of a third dose?

Find out more about COVID-19 vaccines side effects and safety.


When can people expect to be invited for, and to receive, these 3rd doses?

Hospital doctors and GP teams are already identifying and consulting with severely immunosuppressed patients.  The precise timing of an individual’s 3rd dose vaccination will be determined following consultation with their consultant / GP in line with JCVI advice.


Are people in this group also eligible for the flu vaccine?

Some patients who are immunosuppressed are also eligible for the flu vaccine and we would strongly encourage them to get vaccinated to protect themselves against flu, which can have very serious complications for some immunosuppressed patients. Local GP teams and pharmacy services are offering flu vaccines in line with local available supply.

Close contacts of immunocompromised individuals are also eligible for the national influenza vaccination programme, specifically individuals who expect to share living accommodation on most days over the winter and, therefore, for whom continuing close contact is unavoidable.


Will the 3rd dose be given alongside the flu vaccine?

Flu vaccine is not currently included in this advice. Advice on co-administration within this context will be issued in due course.