Skip to main content

What to expect after your COVID-19 vaccination

The COVID-19 vaccine you have received has been approved as safe and effective by the independent Medicines and Healthcare products Regulatory Agency (MHRA). Following detailed review of large studies of safety and effectiveness, the MHRA has approved several different types of COVID-19 vaccines for use in the UK.
 
Each vaccine has been tested in tens of thousands of people in several different countries and shown to be safe and effective. The MHRA continuously reviews the safety of vaccines in use based on all side effects reported by healthcare professionals and the public.
 

Will the vaccine have side effects?

Like all medicines, vaccines can cause side effects. This is because vaccines work by triggering a response in your immune system. These are usually mild and only last a few days, and not everyone gets them. Some COVID-19 vaccines tend to cause more side effects after the first dose and others cause more side effects after the second dose. Even if you do have some side effects after the first dose, it’s still important to have the second dose.
 

Very common side effects in the first day or two include:

 
• having a painful, heavy feeling and tenderness in the arm where you had your injection for several days after the vaccine
• feeling tired
• a headache
• general aches, chills, or flu like symptoms.
 
If your arm is particularly sore, you may find heavy lifting difficult. If you feel unwell or very tired you should rest and avoid operating machinery or driving.
 
An uncommon side effect is swollen glands in the armpit or neck on the same side as you had your vaccination. This can last for about 10 days, but if it lasts longer speak to your doctor. If you are due to have a mammogram in the few weeks after the vaccine, then you should mention that when you attend.
 
A mild fever may occur for two or three days after vaccination but a high temperature is unusual and may indicate you have COVID-19 or another infection.
 
The most important symptoms of COVID-19 are recent onset of any of the following:
 
• a new continuous cough
• a high temperature
• a loss of, or change in, your normal sense of taste or smell
 
If you have any of the symptoms above, stay at home and arrange to have a test. Some health boards are offering tests for a wider range of symptoms, so please check your local health board website.
 
If you need more information on COVID-19 symptoms visit: 111.wales.nhs.uk.
 
If you have any side effects after your vaccine, you can take the normal dose of paracetamol (follow the advice in the packaging) and rest to help you feel better. Do not take more than the normal dose.
 
For information on each COVID-19 vaccine including the contents visit: coronavirus-yellowcard.mhra.gov. uk/productinformation
 
Rarely, some people have an allergic reaction soon after a vaccination. This may be a rash or itching affecting part or all of the body. Even more rarely, some people can have a severe reaction soon after vaccination, which causes breathing difficulties and may cause them to collapse. This is called anaphylaxis and can happen with other medicines and food. These reactions are rare and healthcare professionals are trained to manage them. People who have an anaphylactic reaction can be successfully treated and usually recover within a few hours.
 

What should I do if I am concerned about my side effect symptoms?

 
Any side effects following vaccination normally last less than a week. If your symptoms seem to get worse or if you are concerned, look at: 111.wales.nhs.uk online, and if necessary call NHS 111 Wales on 111 or your GP surgery. If 111 is not available in your area, call 0845 46 47. Calls to NHS 111 Wales are free from landlines and mobiles. Calls to 0845 46 47 cost 2p per minute plus your telephone provider’s usual access charge.
 
If you do seek advice from a doctor or nurse, make sure you tell them about your vaccination (show them your vaccination card if possible) so that they can assess you properly. You can report any side effects online at: coronavirus-yellowcard.mhra. gov.uk/ or via the Yellow Card app.
 

Are there other more serious side effects?

Recently there have been reports of an extremely rare condition involving blood clots and unusual bleeding after vaccination with the AstraZeneca and Janssen vaccines. This is being carefully reviewed but the risk factors for this condition are not yet clear. The JCVI advises no safety concerns with a second dose. Because of the high risk of complications and death from COVID-19, the MHRA, the World Health Organization and the European Medicines Agency have concluded that the balance is very much in favour of vaccination for the vast majority of adults.
 
If you experience any of the following from around 4 days to four weeks after vaccination, you should seek medical advice urgently.
 
  • A new, severe headache which is not helped by usual painkillers or is getting worse
  • An unusual headache which seems to get worse when lying down or bending over or may be accompanied by:
  • Blurred vision, nausea and vomiting
  • Difficulty with your speech
  • Weakness, drowsiness or seizures
  • New, unexplained pinprick bruising or bleeding
  • Shortness of breath, chest pain, leg swelling or persistent abdominal pain
Worldwide, there have also been recent, rare cases of inflammation of the heart called myocarditis or pericarditis reported after 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 you experience:
 
  • chest pain 
  • shortness of breath 
  • feelings of having a fast-beating, fluttering, or pounding heart
 

What do I do next?

If this was your first dose, you should plan to attend your second appointment. You should have a record card with your next appointment written on it. It is important to have both doses of the vaccine to give you the best protection. Remember to take your card to the next appointment.

 

What should I do if I am unwell on the day of my next appointment?

If you are unwell with a fever, it is better to wait until you have recovered to have your vaccine, call to rearrange it and try to have it as soon as possible. You should also not attend a vaccine appointment if you are self-isolating, or waiting for a COVID-19 test or result. Call to rearrange your appointment.
 

Will the vaccine protect me?

The COVID-19 vaccination will reduce the chance of you suffering from COVID-19 disease. It will take a few weeks for your body to build up protection from the vaccine. Like all medicines, no vaccine is 100% effective so you should continue to take the recommended precautions such as social distancing, hand hygiene and face masks to avoid infection. Some people may still get COVID-19 after having a vaccination, but this should be less severe.
 

Can I give COVID-19 to anyone, after I have had the vaccine?

The vaccine cannot give you COVID-19 infection. It will reduce your chance of becoming seriously ill. The vaccines reduce the risk of passing on the virus, but do not completely prevent it. So, it is still important to follow the guidance in your local area to protect those around you. Information can be found at: gov.wales/coronavirus.