Side effects of the coronavirus vaccines

It’s normal to experience side effects after the vaccine. It shows the vaccine is teaching your body’s immune system how to protect itself from the disease, however not everyone gets them.

Most of these are mild and short term. They may include:

  • having a painful, heavy feeling and tenderness in the arm where you had your injection
  • headache or muscle ache
  • joint pain
  • chills
  • nausea or vomiting
  • feeling tired
  • fever (temperature above 37.8°C).

You may also have flu-like symptoms with episodes of shivering and shaking for a day or two.

These common side effects are much less serious than developing coronavirus or complications associated with coronavirus and they usually go away within a few days.

If you feel uncomfortable, you can rest and take paracetamol. Make sure you take paracetamol as directed on the label or leaflet. Remember, do not take medicines that contain aspirin if you are under 16 years of age.

An uncommon side effect is swollen glands in the armpit or neck, on the same side as the arm where you had the vaccine. This can last for around 10 days, but if it lasts longer see your doctor.

If you are due for breast screening (a mammogram) then you should mention that you have had the vaccine when you attend.

These side effects normally last less than a week. If your side effects seem to get worse or if you are concerned, phone NHS 24 free on 111. If you do seek advice from a doctor or nurse, make sure you tell them about your vaccination so that they can assess you properly.

Fever after the coronavirus vaccine

It’s quite common to develop a fever after a vaccination. This normally happens within 48 hours of the vaccination and usually goes away within 48 hours.

You do not need to self-isolate or book a test unless you have other coronavirus symptoms or:

  • you have been told by NHS Test and Protect, or your occupational health team, that you are a close contact of someone who has tested positive for coronavirus
  • you live with someone who has recently tested positive for coronavirus
  • you live with someone who has symptoms of coronavirus

If the fever starts more than 48 hours after the vaccination or lasts longer than 48 hours, you should self-isolate and book a test.

Side effects for each dose

Not all coronavirus vaccines are the same. Some tend to cause more side effects after the first dose, others cause more side effects after additional doses. The very common side effects are the same and should still only last a day or two.

Even if you do have side effects after the vaccine, NHS Scotland advises you get all recommended doses. The full recommended course will give you the best protection against the virus.

Reports of very rare blood clots

The Medicines and Healthcare products Regulatory Agency (MHRA) is carrying out a detailed review of reports of a very rare blood clotting problem affecting a small number of people who have had the Oxford/AstraZeneca vaccine.

The problem can also happen in people who have not been vaccinated and it's not yet clear why it affects some people.

The current reported rate of this condition in the UK is around 15 cases per million first doses given.

The coronavirus vaccine can help stop you from getting seriously ill or dying from coronavirus. For people aged 40 or over and those with underlying health conditions, the benefits of being vaccinated outweigh any risk of clotting problems.

For people under 40, it's currently advised that it's preferable to have either the Pfizer/BioNTech or Moderna coronavirus vaccine.

If you have already had a first dose of the Oxford/AstraZeneca vaccine without suffering any serious side effects you should complete the course (unless there is a medical reason for you not to have the same vaccine).

This includes people aged 18 to 39 years who are health and social care workers, unpaid carers and household contacts of those who are severely immunosuppressed.

Non-urgent advice: When to call 111

Call 111 immediately if you get any of these symptoms starting from around 4 days to 4 weeks after being vaccinated:

  • a severe headache that is not relieved with painkillers or is getting worse
  • a headache that feels worse when you lie down or bend over
  • a headache that's unusual for you and occurs with blurred vision, feeling or being sick, problems speaking, weakness, drowsiness or seizures (fits)
  • a rash that looks like small bruises or bleeding under the skin
  • shortness of breath, chest pain, leg swelling or persistent abdominal (tummy) pain

Oxford/AstraZeneca COVID-19 vaccine and rare blood clots information leaflet

For further guidance please read the Oxford/AstraZeneca vaccination and rare blood clotting information leaflet.

Capillary leak syndrome

Extremely rare reports of capillary leak syndrome have been reported after the Oxford/AstraZeneca vaccine in individuals with a prior history of this condition. You may be offered an alternative coronavirus vaccine.

Heart inflammation

Worldwide, there have also been recent, rare cases of inflammation of the heart called myocarditis or pericarditis reported after coronavirus vaccines, although it is not yet clear that these are caused by the 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. Longer term follow-up is ongoing in the UK and elsewhere to better understand this reaction.

You should seek medical advice urgently if you experience:

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

If you experience heart inflammation after your first dose, you should not get any further doses until your condition has been assessed by an appropriate clinician.

Period problems and unexpected vaginal bleeding

Some women have reported temporary changes in their periods after receiving the coronavirus vaccine. Some women have reported heavier bleeding than usual, delayed periods or unexpected vaginal bleeding. The MHRA and other experts are closely monitoring and evaluating these reports. Longer term follow-up is ongoing in the UK and elsewhere to better understand this reaction.

Current evidence suggests there is no link between period problems or unexpected vaginal bleeding and coronavirus vaccines. The number of reports is relatively low given the number of women who have taken the vaccine and how common period problems are generally. The menstrual changes reported usually do not last long. Whilst uncomfortable or distressing, period problems are extremely common and stressful life events can disrupt with your periods. Changes to the menstrual cycle have also been reported following infection with coronavirus and in women affected by long-COVID.

If you have changes to your periods that are unusual for you, persist over time, or you have any new vaginal bleeding after the menopause, following coronavirus vaccination, please speak to your GP.

More about periods

Reporting side effects

As with all vaccines, you can report suspected side effects through the Yellow Card website.

Can I catch coronavirus from the vaccine?

You cannot catch coronavirus from the vaccine but you can catch it before you get your vaccine and not know you’ve got it until after your vaccine appointment.

Side effects of the Pfizer/BioNTech coronavirus vaccine

A full list of common side effects of the Pfizer/BioNTech vaccine is available on GOV.UK.

Information for UK recipients on Pfizer/BioNTech COVID-19 vaccine

Side effects of the Oxford/AstraZeneca coronavirus vaccine

A full list of common side effects of the Oxford/AstraZeneca vaccine is available on GOV.UK.

Information for UK recipients on Oxford/AstraZeneca COVID-19 vaccine

Side effects of the Moderna coronavirus vaccine

A full list of common side effects of the Moderna vaccine is available on GOV.UK.

Information for UK recipients on Moderna COVID-19 vaccine