A guide to booster vaccination

What is coronavirus or COVID-19?

COVID-19 is a very infectious respiratory disease caused by the SARS-CoV-2 virus and is more serious in older people and those with certain health conditions.

Why you are being offered a COVID-19 booster

Like some other vaccines, levels of protection may begin to wane over time. This booster dose will help extend the protection you gained from your first 2 doses and give you longer term protection.

The booster will help to reduce the risk of you needing admission to hospital due to COVID-19 infection this winter.

Timing of booster

The booster is being offered at least 6 months after your last dose. Like your previous doses, the vaccine will be given in your upper arm.

Protection against severe disease from the first 2 doses seems to decline very slowly. So don’t worry if your booster vaccine is given a few weeks after the 6 months time-point. The booster dose should help to extend your protection into the next year.

Which vaccine you will be offered

You will be given a booster dose of either Pfizer or Moderna vaccine [footnote 1]. These vaccines have already been given to millions of people in the UK.

You will be offered the right vaccine for you which may be the same or different from the vaccines that you had before.

Side effects

Common side effects

As with your previous dose the common side effects are the same for all COVID-19 vaccines used in the UK, and include:

• having a painful, heavy feeling and tenderness in the arm where you had your injection – this tends to be worst around 1 to 2 days after the vaccine
• feeling tired
• headache
• general aches, or mild flu like symptoms

You can rest and take paracetamol (follow the dose advice in the packaging) to help make you feel better. Although feeling feverish is not uncommon for 2 to 3 days, a high temperature is unusual and may indicate you have COVID-19 or another infection.

Although a fever can occur within a day or two of vaccination, if you have any other COVID-19 symptoms or your fever lasts longer, stay at home and arrange to have a test. Symptoms following vaccination normally last less than a week. If your symptoms seem to get worse or if you are concerned, call your GP or Practice Nurse for advice.

Serious side effects

Worldwide, there have also been recent, very rare cases of inflammation of the heart called myocarditis or pericarditis reported after Pfizer and Moderna COVID-19 vaccines.

These cases have been seen mostly in younger men within several days after vaccination. Most of these people recovered and felt better following rest and simple treatments.

You should seek medical advice urgently if, after vaccination, you experience:

• chest pain
• shortness of breath
• feelings of having a fast-beating, fluttering, or pounding heart

If you had serious side effects after any previous dose you may be advised to avoid or delay further vaccination. You should discuss this with your doctor or specialist.

Those who shouldn’t have a booster

There are very few people who should not have a booster.

If you have had a severe reaction to a previous dose of the vaccine you should discuss this with your doctor.

Can you still catch COVID-19 after having the vaccine?

The COVID-19 vaccination will reduce the chance of you suffering from COVID-19. It may take a few days for your body to build up some protection from the booster.

Like all medicines, no vaccine is completely effective – some people may still get COVID-19 despite having a vaccination, but this should be less severe.

If you have not had the first vaccinations

If you have not yet had either of your first 2 doses of the vaccine you should have them as soon as possible.

You will still need the booster but the timing of it will depend on when you had your first 2 doses.

Further information

More information is available at the coronavirus vaccination pages.

Also see guidance on what to expect after vaccination. 

Please read the product information leaflets for UK recipients of the Pfizer and Moderna vaccines for more details on your vaccine, including possible side effects. You can also report suspected side effects on the Yellow Card website.

Footnote 1: AstraZeneca may be an option if this is the vaccine that you had for the first 2 doses. 

Public Health Isle of Man has adapted this information leaflet with kind permission from the UK Health Security England: COVID-19 vaccination: booster dose resources - (gov.uk)

Updated 16 September 2021