MMRV vaccine for UK children: schedule by birth date and what changed

For decades the second year of life brought a combined MMR jab, with chickenpox left unvaccinated in the routine schedule. The NHS now gives MMRV instead, so a child who completes the course is protected against chickenpox as well. The vaccine contains weakened live forms of all four viruses.

The infections it targets spread very easily and can cause meningitis, brain inflammation, pneumonia and hearing loss. Immunity in the community also shields people who cannot be vaccinated, such as newborns and anyone with a weakened immune system.

Because the vaccine was introduced in stages, the NHS sets out the plan according to birth date. Your GP surgery usually contacts you by letter, text, call or email, and you should contact them if an invitation has not arrived.

Babies normally wait until their first birthday because earlier doses may not work as well. The NHS makes an exception for babies aged 6 to 11 months who are travelling to a place with a higher measles risk, who have been in close contact with someone with measles, or who live where there is an outbreak.

The GP can advise on how an early dose fits with the later routine doses. Parents who think their infant might need an early dose should raise it with the GP surgery as soon as the situation arises.

Being a live vaccine, MMRV is not given to children with a severely weakened immune system, whether from a health condition or from medicines that suppress immunity, nor to children who have had anaphylaxis to an ingredient such as gelatine or neomycin. A child with a mild illness and no high temperature can still be vaccinated, but a fever or feeling very unwell is a reason to delay.

Two brands are used in the UK and the NHS describes them as working equally well. One contains a small amount of porcine gelatine, and families who prefer to avoid it can ask the vaccinator for the alternative brand.

Common effects last two to three days and are usually mild. About six to ten days after the jab some children develop a blotchy rash and a temperature, and two to three weeks later some have facial swelling and aching joints, resembling a mild form of mumps or rubella. Neither is infectious.

Around three to four weeks after vaccination a spotty rash may appear near the injection site. This can contain chickenpox virus, so keep it covered with clothing, but as long as the spots are covered the NHS says children can attend nursery. Severe allergic reactions are rare, and vaccinators are trained to respond immediately.

Protection against measles and rubella begins within two weeks and against chickenpox within three. After two doses the NHS gives approximate protection of 99 per cent for measles and rubella, 97 per cent for chickenpox and 88 per cent for mumps. A vaccinated child who still develops mumps usually has milder symptoms.