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Measles: your questions answered

What are measles, mumps and rubella?

They are highly infectious viral childhood diseases that can spread very easily amongst a population. They cause mild to moderate illness but with risks of complications such as seizures (fits), meningitis and encephalitis. Measles and Rubella infection in pregnancy can harm the unborn child, causing deafness, growth problems, heart problems or brain damage. These diseases used to be very common in childhood until a national vaccination programme was introduced in 1988. If you (or your child) have had two doses of MMR vaccine, you are very unlikely to ever contract these diseases.

Haven’t measles, mumps and rubella been eradicated from the UK?

Measles, mumps and rubella are no longer common diseases in the UK, infection rates for mumps and rubella are very low. This was achieved through a successful vaccination programme. However, a fall in the number of children getting vaccinated has led to a rise in measles cases in recent years. It is very important that every child who can safely have the vaccine gets vaccinated so we can keep these diseases and their complications at bay.

How effective is the MMR vaccine?

MMR vaccines are very effective in children over one year old. One dose of MMR vaccine provides over 90% protection against measles and nearly 100% protection against rubella. Two doses of MMR are needed to get full protection against mumps. Children under one year of age still have antibodies from their mother and these can make the vaccine less effective. Even if your child has a dose of MMR before their first birthday (for example if you travel abroad) they still need both of their routine MMR vaccinations.

Can the MMR vaccine cause measles?

The MMR vaccine contains live viruses that have been weakened. The vaccine viruses replicate in the body just like a natural infection. This means that MMR vaccine can commonly cause mild symptoms of measles, mumps or rubella. Symptoms of each disease occur at different times after vaccination, depending on which of the three viruses is replicating. Symptoms tend to be much milder and shorter-lasting than the natural infections. 

Will my child be infectious to other children after their MMR vaccine?

No, there is no evidence that vaccinated children can transmit the vaccine viruses to other people. It is known that from about 7 days after vaccination children can shed vaccine virus particles when they cough or sneeze. The virus particles are weakened and cannot cause disease in other people.

What are the side-effects of MMR vaccine?

Common side-effects after vaccination with MMR include pain, swelling and redness at the injection site, a high temperature (fever), a rash and cold symptoms such as a cough or runny nose. Mild measles symptoms may occur from 6 to 11 days after vaccination. 1 in 50 children may experience swelling of the glands in the face and neck around 3 to 4 weeks after vaccination. Up to 20% of adult women vaccinated with MMR may experience painful, stiff or swollen joints for up to 3 days in the first 3 weeks after vaccination.

I’ve heard the MMR vaccine can cause autism?

Research published in the late 1990s that linked the MMR vaccine to an increased risk of autism has since been discredited. A large number of studies have now investigated the issue and the evidence is overwhelming that MMR vaccine does not cause autism.


Public Health England (PHE); Measles: the green book, chapter 21; Published 20 March 2013, Last updated 31 December 2019; available here.

Summary of medicinal Product Characteristics (SmPC), Priorix® powder and solvent for solution for injection in a pre-filled syringe; GlaxoSmithKline UK Limited, updated 20-May-2020. Accessed online via The electronic Medicines Compendium; available here.

Summary of medicinal Product Characteristics (SmPC), M-M-RVAXPRO® powder and solvent for suspension for injection; Merck Sharp & Dohme (UK) Limited, updated 02-Nov-2021. Accessed online via The electronic Medicines Compendium; available here.

NHS: Health A–Z: MMR (measles, mumps and rubella) vaccine; Last reviewed 10 May 2019; available here.