Chickenpox is one of those ailments that is mild for most kids – but in some cases, it can be very serious.
That’s why the the Joint Committee on Vaccination and Immunisation (JCVI) has now recommended that a vaccine against chickenpox (or varicella) should be added to the UK’s routine childhood immunisation programme.
At present, the chickenpox vaccine is not part of the routine vaccination schedule on the NHS, which means some parents opt to pay privately to protect their kids. But the vaccine can set families back £150 for two doses, per child.
What is chickenpox?
Varicella, or chickenpox, is a highly infectious disease caused by the varicella zoster virus. It mostly affects children but can be caught at any age.
The key symptom is an itchy, spotty rash that crusts over after a period of time. It usually gets better by itself after one to two weeks without needing to see a GP.
Most varicella cases in children are relatively mild, however, some children will go on to develop complications, including bacterial infections such as group A streptococcus.
In rare cases it can cause a swelling of the brain, called encephalitis, an inflammation of the lungs, called pneumonitis, and stroke, which can result in hospitalisation and, in very rare cases, death.
Who is at risk?
Very young infants under four weeks of age are more likely to experience serious illness, as are adults. Pregnant women are particularly at risk as it can cause complications in both the mother and the foetus.
The thinking is that a vaccine would reduce community transmission, protecting the most vulnerable.
What does the vaccine do?
Data from countries with similar programmes suggests the vaccine dramatically reduces circulating chickenpox and prevents the most severe cases in children.
It’s been shown that nine out of 10 children vaccinated with a single dose will develop immunity against chickenpox.
It is given in two doses, and JCVI proposes it should be offered to children at 12 and 18 months of age.
Typical side effects of the jab include soreness and redness around the site of the injection, a mild rash and high temperature.
The immunisation group also recommended a temporary catch-up programme for older children as part of the rollout, in order to boost immunity in the community.
Why now?
The concern is that chickenpox cases were significantly reduced during the pandemic due to social restrictions, meaning there is currently a larger pool of children than usual without immunity.
In 2009 the JCVI ruled out a UK-wide programme as evidence at the time suggested introducing it might cause increased cases of shingles in middle-aged adults.
Varicella can cause shingles in adults that have previously had chickenpox, but they benefit from a boost in their immunity against this when they encounter chickenpox circulating in the community.
It was thought that removing community circulation by vaccinating children would cause a problematic rise in shingles for as long as 20 years, but a recent long-term study from the US disproved that theory.
This evidence, combined with recent research from the University of Bristol that provided new information on the extent of chickenpox’s impact on children and the NHS, opened the door for a UK-wide programme, which the committee has now advised.
When will the vaccine become available on the NHS?
This all depends on how the government responds to the recommendation, as the Department of Health and Social Care will make the final decision on whether to implement the programme.
If approved, it would bring the UK in line with other countries offering routine varicella vaccination, including Germany, Canada, Australia and the United States. All have observed significant decreases in the number of cases of varicella and resulting hospitalisations.
Professor Sir Andrew Pollard, chair of the JCVI, said: “Chickenpox is well known, and most parents will probably consider it a common and mild illness among children. But for some babies, young children and even adults, chickenpox or its complications can be very serious, resulting in hospitalisation and even death.
“Adding the varicella vaccine to the childhood immunisation programme will dramatically reduce the number of chickenpox cases in the community, leading to far fewer of those tragic, more serious cases.
“We now have decades of evidence from the US and other countries showing that introducing this programme is safe, effective and will have a really positive impact on the health of young children.”