First red spots, then small lumps, and finally itchy blisters: most of today's parents have experienced chickenpox first-hand. Whilst some were covered in blisters and still bear the scars today, others got off lightly with just a few blisters.
Until recently, chickenpox was regarded as a childhood illness that one simply had to get over. It was a nuisance, but generally harmless. Vaccination against the chickenpox virus was recommended for young people who had not yet had the disease. This is because the risk of severe cases and complications increases with age.
That has changed over the past three years. In 2023, the vaccine against the varicella-zoster virus, which causes chickenpox, was added to the Swiss Immunisation Schedule. The Federal Commission on Immunisation (EKIF) and the Federal Office of Public Health (FOPH) recommend vaccinating infants at 9 and 12 months of age.
The causative agents of two diseases
How did this come about? Is chickenpox not as harmless as is commonly believed? «Nothing has changed in the assessment of chickenpox,» says Anita Niederer, Head of Infectious Diseases and Infection Prevention at the Eastern Switzerland Children's Hospital and a member of EKIF. There is another, very important reason for the vaccination recommendation, namely shingles. The varicella-zoster virus is, in fact, a pathogen that causes two diseases.
Shingles is a rash that is often painful. Even after the rash has cleared up, the pain can persist, sometimes for years.
Anyone who catches it develops chickenpox. Although those affected are then immune to reinfection, the virus remains in the body. It belongs to the herpes virus family and retreats into the nerve cells. If the cell membranes become damaged, the virus is reactivated and causes shingles, also known as herpes zoster.
This is a rash that is often painful. It can appear anywhere on the body; it becomes particularly dangerous if the face, eyes or ears are affected. This can lead to loss of vision or hearing, balance problems or facial paralysis. Even after the rash has subsided, the pain can persist for weeks, months or even years.
One in three people develop shingles
The risk of developing shingles increases from the age of 50. «As we get older, our cells become less functional and are therefore less able to keep the virus at bay,» explains Anita Niederer. Other triggers include stress, medication or a weakenedimmune system.
One in three people will develop shingles at some point in their lives. Currently, this amounts to around 30,000 people a year in Switzerland, of whom 2,000 to 3,000 require hospitalisation. Since 2022, the FOPH has therefore recommended that people aged 65 and over get vaccinated against herpes zoster. This is a different vaccine from the one against the varicella-zoster virus.
It is mainly parents who know someone in their circle of friends and family who has had shingles who have their children vaccinated.
Jan Teller, paediatrician
The fact that babies are now being vaccinated against the virus is also down to figures from the US. These show that people who have been vaccinated against the chickenpox virus have a 78 per cent lower risk of developing shingles later in life. In the US, babies have been immunised against it since 1995, which is why the vaccination coverage rate there is over 95 per cent. So why is Switzerland only following suit now?
Combination vaccine
Discussions about introducing the vaccine for infants were already taking place in this country as early as 2004. «At the time, however, there were various uncertainties,» explains Anita Niederer. For example, it was unclear whether one or two doses were needed to provide long-lasting protection. Furthermore, no combined vaccine was available.
Today, infants are vaccinated against the varicella-zoster virus alongside measles, mumps and rubella. «After all, there were concerns that there might be more cases of shingles because adults who have already recovered are less likely to come into contact with the virus,» said the infectious disease specialist.
The research had assumed that any exposure to the pathogen would strengthen the immune system and prevent shingles from developing. This fear has not been borne out. On the contrary.
This helps relieve itchy blisters
- The chickenpox virus is highly contagious. 90 per cent of people who have never had chickenpox will catch it after coming into close contact with an infected person for just a few minutes.
- The virus spreads via respiratory droplets in the air and through contact with the fluid from the blisters. The incubation period – that is, the time between infection and the onset of symptoms – is between 10 and 21 days.
- Those affected are contagious from one to two days before the blisters appear and remain so until the last blisters have scabbed over.
- Before the itchy rash typical of chickenpox appears, sufferers often experience a mild fever, tiredness, headaches and aching limbs, as well as a loss of appetite. The rash usually spreads from the head down over the torso and across the whole body. On average, the acute phase of the illness lasts seven to ten days.
- Lotions or foam sprays are available from pharmacies to relieve the itching; these can be applied to the blisters. If the itching is causing the child significant distress, antihistamines in drop form may also help, although these must be prescribed by a doctor.
- Home remedies can also provide relief. For example, you can dab the blisters with household vinegar or a cooled elderflower infusion. A short sitz bath in cool water or cold compresses soaked in chamomile tea can also help.
- It is important that children avoid picking at the blisters as much as possible. It therefore helps to keep their fingernails short. Picking at the blisters can lead to infections and permanent scarring.
Asymptomatic course
Anita Niederer is cautious about figures. «It will take a few more years to see a significant effect,» she says. «The first cohorts to be vaccinated in the US as children are now just 30 years old.» Furthermore, the live virus introduced into the body via the vaccine can also trigger shingles. «However, this is very much attenuated,» says the infectious disease specialist.
As a result, the immune system requires far fewer resources to keep the pathogen under control. The vaccine is 92 per cent effective in preventing chickenpox, which explains some of the cases of shingles among those who have been vaccinated. Furthermore, chickenpox can also be asymptomatic. This means that someone may believe they have not yet had the disease and therefore gets vaccinated.
«In this case, he is considered to be vaccinated, but he is still carrying the wild virus and therefore faces the normal risk of developing shingles,» explains Jan Teller, who has been running a paediatric practice in Langnau im Emmental, Bern, for 23 years.
Booster jabs for older children
So what does this mean for children born before 2023 who have never had chickenpox? The FOPH and the EKIF recommend catching up on the vaccination. This requires two doses administered at least four weeks apart. «The vaccine is well established, very safe, effective and causes few side effects,» says Anita Niederer.
The latter may include pain or redness at the injection site. Some time later, usually one to two weeks after the injection, you may experience a fever, flu-like symptoms or a mild rash lasting one or two days.
Jan Teller also says: «Judging by the feedback I've received, the vaccine is very well tolerated.» An estimated 80 per cent of parents at his practice have had their children receive the booster jab – particularly parents who know someone in their circle who has had shingles are opting to do so.
If the child has blisters on their scalp, it is almost certainly chickenpox.
Anita Niederer, infectious disease specialist
Reasons for having the varicella-zoster vaccine
For Anita Niederer, it is not just the reduced risk of shingles that makes the varicella-zoster vaccine worthwhile. Rather, she believes it makes sense to prevent infection with an unpleasant and potentially dangerous virus. After all, there are another 300 viruses that children can use to build up their immune systems.
This is because, in rare cases, chickenpox can also lead to serious complications that can be fatal. These include, for example, necrotising fasciitis. In this condition, bacteria enter the body through the broken blisters and cause tissue to die.
If left untreated, this can quickly lead to multiple organ failure. Other serious complications include inflammation of the cerebellum, which can cause permanent movement disorders, as well as meningitis and pneumonia.
No need to see a doctor
Generally speaking, a child with chickenpox does not need to see a doctor. According to Anita Niederer, there is one tell-tale sign that can confirm the diagnosis: «If the child has blisters on the scalp, it is highly likely to be chickenpox.» With other types of rash, the scalp is not usually affected.
Parents should take action if their child stops drinking, appears listless or complains of severe pain in an area where there are no visible external signs. The latter is a sign of a bacterial infection of the muscle or tissue.
Anita Niederer does not yet believe that the varicella-zoster virus is circulating much less widely and that unvaccinated children are less likely to catch it. However, if vaccination coverage increases over the next few years, this will be the case.
«In this way, we are also protecting people who cannot get vaccinated themselves but are at greater risk of complications,» she says, referring, for example, to newborns or children with cancer whose immune systems are weakened.
