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Varicella (chickenpox) is a highly contagious disease caused by the varicella zoster virus that occurs most commonly in young children. Varicella typically presents with an itchy, blistering rash, preceded by fever and malaise. Most cases in children are mild and self-limiting. However, some children develop complications, including bacterial infection of skin lesions (including group A streptococcus) and in rare cases, encephalitis, pneumonitis and stroke. These complications can result in hospitalisation and very rarely may result in death.
The true extent of hospitalisations caused by varicella is underestimated through routine data sources due to errors in coding. Many admissions are due to secondary complications, which are not recorded as a hospital admission related to varicella. Additional, less understood complications, may also be missed in current data. The Joint Committee on Vaccination and Immunisation (JCVI) is an expert scientific advisory committee which advises the UK government on vaccination and immunisation matters. JCVI reviewed evidence from international varicella programme data, cost-effectiveness modelling, and disease burden in the UK. They have recommended the introduction of a routine varicella vaccination programme in the UK commencing 1 January 2026. The vaccine used is MMRV, which helps protect against measles, mumps, rubella, and varicella (chickenpox).
There is a selective MMRV catch-up programme for older children to help accelerate control and to further reduce transmission in the population. Children will be invited and encouraged to attend if they have not yet had chickenpox vaccine or disease.
As has been shown in other countries which include varicella in their routine vaccination schedule, a two-dose MMRV schedule is predicted to significantly decrease the number of cases of varicella infection seen in childhood. The programme will prevent severe cases, and other serious varicella-related complications, which while rare, may have otherwise resulted in hospitalisation or other serious outcomes.
The MMRV vaccine helps protect against measles, mumps, rubella and chickenpox.
The MMR vaccine helps protect against measles, mumps, and rubella.
From 1 January 2026 the MMRV vaccine replaces the MMR vaccine in the routine childhood immunisation schedule in Wales.
From 1 January 2026:
The first dose of MMRV is given to babies at 12 months and the second dose at 18 months.
The 18-month visit is a new vaccination appointment. During this visit, a fourth dose of the multivalent 6-in-1 vaccine (diphtheria, tetanus, whooping cough, polio, Hib, and hepatitis B) is also given.
There is a selective MMRV catch-up programme for older children aged over 3 years and 4 months to under 6 years old on 1 January 2026 (Date of Birth: 1 January 2020 – 31 August 2022) to help accelerate control and to further reduce transmission of chickenpox in the population. This programme will be delivered between 1 November 2026 to 31 March 2028.
For details on selective catch-up cohort (greater than 3 years 4 months to less than 6 years) see:
**Frequently asked questions - Currently being updated**
The MMR vaccine is no longer available for the NHS routine childhood programme from 1 January 2026.
The MMR vaccine is still available for administration outside of the routine childhood programme for people who need it. This includes older children and adults who have not received two doses of MMR and are not eligible for MMRV.
For details on non-routine vaccinations see:
**Frequently asked questions - Currently being updated**
To check eligibility and timing for MMRV and MMR vaccines, use the MMRV Eligibility Tool available at:
phw.nhs.wales/MMRVEligibilityTool
Changes to the childhood immunisation schedule - Information for health professionals
For details on the routine immunisation schedule in Wales, visit:
Routine immunisation schedules for Wales
Measles, mumps and rubella are notifiable diseases in Wales.
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:
rash for at least three days
fever for at least one day, and
at least one of the following – cough, coryza or conjunctivitis.
Mumps is an acute viral illness caused by a paramyxovirus, characterised by parotid swelling. Symptoms like fever, headache, malaise, myalgias, and anorexia may also occur. 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.
Varicella (chickenpox) is an acute, highly infectious disease caused by the varicella zoster virus. Varicella spreads through direct contact or droplets, with a one to three-week incubation period.
A mild fever and malaise may occur before the rash, which starts on the face and scalp, spreading to the trunk and abdomen. The rash lasts for three to four days, then dries into scabs, and may be sparse or extensive.
Varicella is more serious in very young infants, adults, pregnant women (affecting both mother and foetus), and immunosuppressed adults.
While most varicella (chickenpox) cases in children are mild and resolve without medical treatment. Some children develop complications, such as bacterial skin infections, encephalitis, pneumonitis, and stroke, potentially leading to hospitalisation or, rarely, death.
Data shows that severe varicella (chickenpox) infections often lead to complications that are both common and expensive, adding strain to healthcare services. It is likely that the actual number of hospital admissions due to varicella is underreported. Many of these hospitalisations arise from secondary complications such as invasive group A streptococcal infections or childhood strokes, which are often not recorded as being related to varicella. There may also be other secondary complications related to varicella that are not recorded or fully understood with the existing data.
Herpes zoster (shingles) results from reactivation of the varicella (chickenpox) virus. It's more common in the elderly and immunosuppressed individuals. The UK has had a universal shingles vaccination programme in place since 2013 in older adults. For more information, visit Shingles - Information for health professionals
The MMRV vaccine is a safe and effective combined vaccine that helps protect against four serious diseases measles, mumps, rubella and chickenpox. The vaccine contains live attenuated measles, mumps, rubella and varicella viruses.
MMRV has been used in other countries including the USA, Canada, Australia and Germany for many years. Countries that have implemented varicella vaccination programmes have reported a significant decline in varicella cases and associated hospitalisations.
MMRV vaccine summary of product characteristics
The NHS routine childhood immunisation schedule in Wales programme uses two MMRV vaccines:
The vaccines are considered clinically equivalent and interchangeable, although Priorix-Tetra® may be preferred for children who do not accept pork gelatine.
Priorix-Tetra® will remain available for customers serving communities that do not accept vaccines containing pork gelatine. Ordering of Priorix-Tetra® via ImmForm may be subject to a cap, however, an option to request an increase will be provided.
A ‘varicella-only’ vaccine is not offered in the NHS routine or selective programmes.
The MMR vaccine is a well-established, safe and effective combined vaccine that helps protect against measles, mumps and rubella. It is a live preparation of freeze-dried live attenuated measles, mumps and rubella.
The MMR vaccine is highly effective and has an excellent safety record. Since it was introduced in 1988, measles, mumps and rubella have become rare in the UK. But sometimes outbreaks happen, especially of measles, when not enough people get vaccinated.
MMR vaccine summary of product characteristics
Two MMR vaccines are currently used in the UK. These are called MMRvaxPro® and Priorix®. MMRvaxPro® contains pork gelatine. Priorix® does not contain gelatine.
Guidance in the Green Book supersedes the summary of product characteristics (SmPC).
More information about the MMR-containing vaccines can be found in the Green Book chapters for each disease. See Clinical resources and information section.
All healthcare professionals should make every contact count and take advantage of existing opportunities to check vaccination status and administer or arrange MMR-containing vaccinations for:
all children and young adults who have not been vaccinated
new entrants to the UK at General Practice registration consultation and immigration assessments
postnatal women through health visiting assessments and six-week maternal checks
women accessing preconception or fertility services.
MMR should be used to protect women of childbearing age and healthcare workers against rubella infection.
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 mhra.gov.uk/yellowcard (external site), by downloading the Yellow Card app, or by calling 0800 731 6789 (Monday to Friday, 9am to 5pm).
** Currently being updated**
MMRV programme: information for healthcare practitioners - GOV.UK (external site)
For details about changes to the routine childhood immunisation schedule please see:
Joint Committee on Vaccination and Immunisation (JCVI) guidance
Changes to the childhood immunisation schedule: JCVI statement - GOV.UK (www.gov.uk) (external site)
MMRV programme: information for healthcare practitioners - GOV.UK (external site)
Welsh Health Circulars and Welsh Government letters
Public Health Wales guidance
Policy and guidance can also be found on the Public Health Wales Policy, letters and Welsh Government SharePoint page (access for NHS healthcare staff)
The Complete Routine Immunisation Schedule includes information about routine and non-routine vaccinations.
Public Health Wales has produced healthcare professionals awareness raising sessions
on the MMRV vaccine and measles:
Recorded slide sets
Webinars
Training slides
These can be accessed via the E-learning page and the Training Resources and Events page.
Measles resources
Mumps resources
Rubella resources
Varicella (chickenpox) resources
MMRV vaccine resources
MMR immunisation programme toolkit for primary care (Bilingual) This document summarises measles and MMR information to support health professionals and their patients. We encourage all staff to have an awareness of the MMR information sources provided in this toolkit.
MMR A3 Poster (Bilingual) Key messages for the public about the MMR vaccine
Is it Measles poster (Bilingual) Key messages for primary care providers
MMR prison resources
PGD templates for vaccines can be found on the Welsh Medicines Advice Service (external site) page.