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What to expect after your COVID-19 vaccination

The COVID-19 vaccine you have received is amongst the first to be approved as safe and effective by the independent Medicines and Healthcare products Regulatory Agency (MHRA). Each vaccine has been tested in tens of thousands of people in several different countries and shown to be safe and effective.

Will the vaccine have side effects?

Like all medicines, vaccines can cause side effects. These are usually mild and only last a few days, and not everyone gets them.

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 include: 

  • having a painful, heavy feeling and tenderness in the arm where you had your injection for several days after the vaccine

  • feeling tired

  • headache

  • general aches, or mild 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 swelling of the local glands.

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 for any additional symptoms that would make you eligible for a test in your area. If you need more information on symptoms visit NHS 111 Online.

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 exceed the normal dose. For information on each COVID-19 vaccine including the contents visit:

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 nurses are trained to manage them. People who have an anaphylactic reaction can be successfully treated and usually recover within a few hours.

Symptoms following vaccination normally last less than a week. If your symptoms seem to get worse or if you are concerned, look at online, and if necessary call NHS 111 Wales on 111 or your GP surgery. If 111 if 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: or via the Yellow Card app.

What do I do next

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 not well when it is my next appointment?

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

Will the vaccine protect me? 

The COVID-19 vaccination will reduce the chance of you suffering from COVID-19 disease. It may 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, now I have had the vaccine?

The vaccine cannot give you COVID-19 infection. The vaccine will reduce your chance of becoming seriously ill. We do not yet know whether the vaccines will stop you from catching and passing on the virus. So, it is still important to follow the guidance in your local area to protect those around you. Information can be found at