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Changes to the childhood immunisation schedule in Wales are taking place in 2025 and 2026.
Included in these changes:
To find out more about these changes, including a table on MMR eligibility, go to Changes to the childhood immunisation schedule - Information for health professionals
Further details about the childhood immunisation schedule in Wales are also available at Changes to the childhood immunisation schedule
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Measles mumps and rubella are notifiable diseases in the UK.
Measles is one of the most highly communicable infectious diseases. It is spread by airborne or droplet transmission. The incubation period is about ten days.
Measles is caused by a morbillivirus of the paramyxovirus family. The prodromal stage is characterised by the onset of fever, malaise, coryza, conjunctivitis and cough. The rash starts at the head, spreading to the trunk and limbs over three to four days.
Koplik spots (small red spots with blueish/white centres) may appear on the mucous membranes of the mouth one to two days before the rash appears.
Individuals are infectious from the beginning of the prodromal period (when the first symptom appears) to four days after the appearance of the rash.
The following features are strongly suggestive of measles:
Mumps is an acute viral illness caused by a paramyxovirus, characterised by parotid swelling. Symptoms like fever, headache, malaise, myalgias, and anorexia may also appear. Asymptomatic cases are common in children.
Mumps is spread through airborne or droplet transmission, with an incubation period of around 17 days. People are infectious from a few days before to after parotid swelling onset.
The mumps virus frequently affects the nervous system. Neurological complications, including meningitis and encephalitis, can occur.
Common complications include pancreatitis, oophoritis, and orchitis. Sensorineural deafness, nephritis, arthropathy, cardiac abnormalities, and rarely, death have been reported.
Rubella is caused by a togavirus. It may begin with non-specific symptoms like low-grade fever, malaise, coryza, and mild conjunctivitis. The rash is usually transitory, and seen behind the ears, face, and neck. Clinical diagnosis can be unreliable due to the fleeting nature of the rash.
Rubella spreads via droplet transmission, with an incubation period of 14 to 21 days.
Complications include thrombocytopaenia and post-infectious encephalitis. In adults, arthritis and arthralgia may occur.
Maternal rubella infection during pregnancy can lead to foetal loss or congenital rubella syndrome (CRS), which includes cataracts, deafness, cardiac abnormalities, microcephaly, growth retardation, and inflammatory lesions. Infection in the first eight to 10 weeks of pregnancy can cause damage in up to 90% of surviving infants, often resulting in multiple defects.
The MMR vaccine is a safe and effective combined vaccine that helps protect against three serious diseases: measles, mumps and rubella.
Up to 31st December 2025: The first dose of the MMR vaccine is given at 12-months, and the second dose is given at 3 years and 4 months.
From the 1st of January 2026:
The Complete Routine Immunisation Schedule for Wales is available on our website at: Routine immunisation schedules for Wales
For further details on these changes, including a table outlining MMR eligibility, please visit: Changes to the childhood immunisation schedule - Information for health professionals
For answers to frequently asked questions about MMR, including updates on the childhood immunisation schedule for Wales, please visit the following links:
The first dose of the MMR vaccine is offered between 12 and 13 months of age. By that age the immunity a baby had received from their mother against the diseases will have faded.
The Joint Committee on Vaccination and Immunisation (JCVI) has recommended that, the age that children get their second MMR vaccine changes from 3 years 4 months to 18 months.
From the 1st of January 2026 children receive their second dose of MMR vaccine at 18 months.
The second dose of the MMR vaccine has been moved forward to improve vaccine coverage and reduce measles outbreaks. In areas of London where this has already been done, vaccine coverage increased. Ensuring high vaccine uptake is essential and the JCVI believes the potential benefit of increasing MMR coverage justifies the additional routine immunisation visit at 18 months.
The MMR vaccine was introduced in 1988. The vaccine is a live preparation of freeze-dried live attenuated measles, mumps and rubella. It is highly effective and has an excellent safety record.
More information about the vaccine can be found in the Green Book chapters for each disease. See Clinical resources and information section.
Two MMR vaccines are currently recommended for use in the UK. These are:
Guidance in the Green Book supersedes the summary of product characteristics (SmPC).
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. You should report suspected adverse reactions of vaccines and medicines online at hra.gov.uk/yellowcard (external site), by downloading the Yellow Card app, or by calling 0800 731 6789 (Monday to Friday, 9am to 5pm).
All healthcare professionals should make every contact count and take advantage of existing opportunities to check vaccination status and administer or arrange MMR vaccinations for:
MMR should be used to protect women of childbearing age and healthcare workers against rubella infection.
For details about changes to the routine childhood immunisation schedule for Wales, please see: Changes to the childhood immunisation schedule: JCVI statement - GOV.UK (www.gov.uk) (external site)
Vaccination programme recommendations from the Joint Committee on Vaccination and Immunisation (JCVI) and Welsh Government policy can be found at the links below.
Joint Committee on Vaccination and Immunisation - GOV.UK (external site) (read JCVI publications and statements; search e.g. MMR).
The Complete Routine Immunisation Schedule includes information about routine and non-routine vaccinations.
Welsh Health Circulars and Welsh Government letters:
Policy and guidance can also be found on the Public Health Wales Policy, letters and Welsh Government SharePoint page (access for NHS healthcare staff)
Online courses and training materials about a number of vaccines and diseases can be accessed via the E-learning page.
Further immunisation training information and resources are provided on the Training Resources and Events page.
Mumps: epidemiology, surveillance and control (UKHSA) (external site)
PGD templates for vaccines can be found on the Welsh Medicines Advice Service (external site) page.