Mild or intermediate reactions to MMR

Most children who have the MMR vaccine do not have any problems with it or if reactions do occur they are usually mild. (See 'No reactions to MMR'.) The risk of the MMR vaccine causing serious harm, or death, is extremely small.

The overwhelming majority of parents believe in immunisation for their children. We have however included here the views of a few parents who do not believe immunisation is right for their own child based on their personal beliefs. Their views represent a small proportion of the population.

The most likely reactions after having the MMR vaccine are mild symptoms that are like the diseases that the immunisations protect children from, such as redness, pain and/or swelling at the injection site, a mild rash, and a mild fever (affecting up to 1 in 10 people at each dose- Oxford University - Oxford Vaccine Group June 2019). They usually last for a short duration and are not infectious to others. If these problems occur, it is usually within 7-10 days after the injection. Swelling of the glands in the cheeks or neck can also occur two to three weeks after the injection but it is rare. 

Intermediate reactions can occur such as a febrile convulsion (a fit) (affecting up to 1 in 1000 people at each dose - Oxford University - Oxford Vaccine Group June 2019). Fits are more common as a result of measles infection than they are as a result of the MMR vaccine. A febrile fit can happen with a fever from any cause and is treated by keeping the child cool.

In about 1 in every 24,000 doses of vaccine, a skin rash of small, bruise-like spots develops up to six weeks after vaccination (called idiopathic thrombocytopenic purpura, or ITP). This can also occur after measles or rubella infection, and is more common as a result of the diseases than as a result of the vaccine.You should consult your doctor if your child experiences fits or a rash that looks like ITP after vaccination. (Oxford University - Oxford Vaccine Group June 2019)

A small number of parents we interviewed mentioned that their child had a small swelling where the injection was given that had disappeared quickly. One mother said her son had a mild rash during the week after his MMR vaccine, which went after twenty-four hours.   

A couple of mothers recalled that their daughters had been irritable or down in the dumps for a few days, which had worried them at first. But these reactions had passed and they had returned to being their normal selves.

We did not interview any parent whose child had an intermediate reaction to the MMR vaccine as listed above.  

One mother we interviewed talked about the unusually strong local reaction her children had after the second dose of MMR. This reaction was extremely rare. In her son's case, swelling which started in the arm where the injection was given spread across his chest and he had to be in hospital on antibiotics for three days.

Last reviewed August 2019.
Last updated August 2019.



Please use the form below to tell us what you think of the site. We’d love to hear about how we’ve helped you, how we could improve or if you have found something that’s broken on the site. We are a small team but will try to reply as quickly as possible.

Please note that we are unable to accept article submissions or offer medical advice. If you are affected by any of the issues covered on this website and need to talk to someone in confidence, please contact The Samaritans or your Doctor.

Make a Donation to

Find out more about how you can help us.

Send to a friend

Simply fill out this form and we'll send them an email