Covid-19 Coronavirus

A guide to booster vaccination for individuals aged 18 years and over and those aged 16 years and over who are at risk

People aged 18 years and over, and those aged 16 years and over who are at risk (including health and social care workers) will be offered a booster dose of coronavirus (COVID-19) vaccine. Check you are eligible before using the online booking system to receive your COVID-19 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.

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

Protection against severe disease from the first 2 doses seems to decline very slowly. Boosting your immunity should help to extend your protection into next year and may give broader protection against new variants.

Timing of booster

The booster is being offered to those most vulnerable first, and will then be rolled down to younger age groups. Your appointment should be at least 3 months from your last dose, but you may be called later depending on your age group.

Which vaccine you will be offered

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

Studies have shown that you only need a half dose of Moderna to boost the immune system well. This half dose of Moderna is expected to have a low rate of side effects including myocarditis.

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 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.

You can also report suspected side effects of vaccines and medicines through the Yellow Card scheme.

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 of 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.

If you have a COVID-19 positive result, when can you have a booster?

You will still need the booster but you should wait at least 4 weeks.

Translations into other languages

Public Health England has also produced documents in other languages.

These documents explain the COVID-19 vaccination, who is eligible and who needs to have the vaccine to protect them from coronavirus (COVID-19).

Translated copies are available in these languages English, English large print, Albanian, Arabic, Bengali, Brazilian Portuguese, Bulgarian, Chinese, Estonian, Farsi, Greek, Gujarati, Hindi, Latvian, Lithuanian, Panjabi, Polish, Romanian, Russian, Somali, Spanish, Turkish, Twi, Ukrainian and Urdu.

See: COVID-19 vaccination: booster dose resources

Disclaimer: The contents of these translated documents may differ slightly from local literature produced to support the Isle of Man COVID-19 Vaccination Programme.

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 Agency: COVID-19 vaccination: booster dose resources - (

Updated 2 December 2021

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