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FAQs for the COVID-19 Vaccination Booster Programme

Is it safe for an individual to receive a COVID-19 booster vaccine that is different to the initial two doses?

Yes, data from the COV-Boost trial indicates that booster doses of COVID-19 vaccines are generally well tolerated and can provide a substantial increase in vaccine-induced immune responses.

In particular, mRNA (Pfizer / Moderna) vaccines provide a strong booster effect, regardless of whether the primary course was with the Pfizer or the AstraZeneca vaccine. The vast majority of booster vaccines in Wales will be an mRNA vaccine.

Does a booster campaign mean that the vaccines are not effective?

The vaccines are highly effective, especially against severe disease. Protection against hospitalisation is estimated at around 95% after the second dose of vaccine.

Recent UK data has shown early signs of a lowering in the levels of protection that is most evident amongst older individuals who completed their primary vaccine course a longer time ago.

Taking a precautionary position, JCVI considers that on balance, it is preferable to ensure protection is maintained at a high level throughout the winter months in adults who are more vulnerable to severe COVID-19, rather than implement a booster programme only when large numbers of persons have developed severe COVID-19

Will the COVID-19 booster vaccine protect against current and emerging variants of the virus?

Vaccines are our best defence against emerging variants of COVID-19 and have shown to mitigate the severity of infections in those who go on to test positive for COVID-19. 

As well as working closely with manufacturers, scientists are continually seeking to better understand the impact of some variants of concern on the vaccines currently in deployment. The programme is being constantly reviewed in light of new evidence and advice from experts, including the JCVI.

Vaccines have been highly effective at preventing hospitalisations and deaths due to COVID-19 since their roll-out, even with the emergence of the Delta variant. Public Health Wales stats here:$FILE/Survey%20of%20vaccine%20status%20in%20cases%20and%20hospital%20inpatients.pdf

The booster programme will ensure that those who are most vulnerable to COVID-19 receive the maximum protection as we head into the winter months, and continue to safeguard the NHS.

Throughout this global pandemic, the government has been guided by the latest scientific advice. We will be monitoring the effect of the vaccine, including the booster campaign on the population, as well as emerging variants of concern, and reviewing our approach as appropriate.

If people received their first doses of vaccine outside the UK, are they eligible for a booster in UK?

Guidance has been issued for clinicians who need to decide whether to provide further vaccination to individuals vaccinated outside the UK. (COVID-19 programme guidance for healthcare workers (

Whether additional doses are recommended, including any booster doses, will be set out in this guidance. This guidance will be regularly reviewed as more data becomes available.

Will those who received a 3rd primary dose due to immunosuppression be eligible for a booster and what is the recommended dose interval between 3rd primary dose and booster dose?

Third primary doses are being given to bring the levels of immunity in people with severe immunosuppression closer to that which non-immunosuppressed achieve from two doses.

This advice on booster vaccination is distinct from, and does not supersede, recent advice from JCVI regarding a third primary vaccine dose for persons who are severely immunosuppressed. JCVI will review at a later date whether they will require a further booster dose following completion of their three-dose primary vaccine course.

Will Boosters be required to generate a COVID PASS?

We are considering whether we will include boosters in any potential certification policy. Boosters are not currently required to generate a COVID Pass. This will be kept under review and an update will be provided in due course including on whether boosters will be required to generate a COVID Pass in future.

Is everyone who is eligible for a free flu vaccine also eligible for a COVID-19 booster vaccine?

While most people that are eligible to receive a free flu vaccine on the NHS will also be eligible to receive the COVID-19 booster, there are some slight differences as flu and COVID-19 are different viruses meaning expert recommendations on who should get the jabs are slightly different.

All cohorts eligible for the flu vaccination are able to get their vaccination at any time during the flu vaccination programme (beginning in September).

Meanwhile, expert advice is that COVID-19 boosters are phased starting with those who are most likely to become seriously ill from COVID-19.

Is having the booster jabs and the flu jabs together safe?

Please take up the offer of the flu and booster jabs as soon as they are offered. There is no need to leave a gap between each jab. The Joint Committee on Vaccination and Immunisation (JCVI) has advised that it is safe for flu and booster vaccines to be administered at the same time or at any time after - no spacing is required

Most people won’t be offered their flu and COVID-19 booster vaccines at the same time. Your booster vaccine will in most cases be given at a COVID-19 Vaccination Centre, while your flu vaccine will in most cases be given at your GP surgery. Most people will receive separate appointment letters for both jabs.

Have the vaccines been authorised for use as boosters?

The COVID-19 vaccines are all authorised under conditional marketing authorisations (CMAs) which means where data supports it, the JCVI can advise their use as a booster dose. The JCVI considered the benefits and safety risks before advising to proceed with boosters.

On 9 September, the Medicines and Healthcare products Regulatory Agency (MHRA) confirmed that Pfizer, Moderna and AstraZeneca vaccines are safe to use as a third dose.

Which vaccine will be administered during the COVID-19 booster vaccination programme?

After reviewing data on booster responses from different combinations of COVID-19 vaccines, JCVI advises a preference for the mRNA vaccines i.e. Pfizer and Moderna, irrespective of which vaccine someone has received as their primary course. There is good evidence that these are well tolerated as a booster dose and will provide a strong response. 

Individuals are not offered a choice of vaccine as it will depend on which vaccines the programme is deploying at that point in time, based on JCVI guidance and the vaccine supply available.

For the small number of people where mRNA vaccines cannot be taken e.g. due to allergies, vaccination with the AstraZeneca vaccine may be considered for those who received AstraZeneca vaccine in their primary course. 

What is the COVID-19 booster programme?

We are offering a booster dose of vaccine to those most vulnerable to COVID-19, and the people who care for them.

It will be offered at least 6 months after the second dose, starting with people living or working in care homes, and frontline health and social care staff.

The Joint Committee on Vaccination and Immunisation (JCVI) looked at evidence from around the world and advised that COVID-19 boosters should be offered to certain groups.

They said this is to maintain protection against severe COVID-19 throughout the winter months and to protect the NHS

Booster vaccine for people who are immunosuppressed
Why is a booster vaccine being offered?
Who is eligible for a booster vaccine?
Which vaccine will be used for my booster jab?
I'm under 50 years old. When will I need a booster vaccine?
Concerns about getting vaccinated

The vast majority of clinical queries can be discussed at our vaccination centres as part of your appointment. Our experienced clinical staff can take the time to discuss any concerns or questions you have before you make a decision on whether or not to go ahead with vaccination.

If you have a clinical query which cannot wait until the day of your appointment, please contact our COVID-19 Vaccination Clinical Advisors at

Please note that this email address should only be used for clinical queries. Information on eligibility, how you will be contacted, and what you should do if your vaccination information is incorrect can be found elsewhere on our Frequently Asked Questions pages.