Chickenpox / Shingles

Chickenpox (varicella) is usually harmless in healthy children. In order to avoid complications, vaccination is recommended for 11- to 39-year-olds who have not had chickenpox and for certain high-risk groups from the age of 12 months.

Pathogen and transmission

Chickenpox (varicella) is a highly contagious disease caused by the varicella zoster virus (VZV). VZV can also case shingles later in life. The virus is easily transmitted from person to person through the air in respiratory droplets. The blister fluid of a chickenpox rash or shingles is also infectious. Chickenpox usually occurs in childhood as an unpleasant but generally mild and harmless disease. An infected person is already contagious two days before the rash develops and until the final blisters have formed scabs.

Infection with VZV usually confers life-long immunity to chickenpox, but the viruses remain in the body and may eventually cause shingles later in life.

Clinical picture

Chickenpox (Varicella)

Mild fever and tiredness develop two to three weeks after infection, followed by a rash that is often itchy. The little red spots develop into pustules and blisters that ultimately dry out and form scabs that drop off.

People usually catch chickenpox only once in their lifetime.

However, complications such as bacterial skin infections can occasionally occur. Serious complications such as pneumonia, encephalitis and meningitis are rare. If the disease does not develop until adulthood, the risk of complications is higher than in children. Newborns, people with a compromised immune system, pregnant women (pneumonia) and their unborn children (high risk of malformation) are at particular risk.

Shingles (Herpes zoster)

After a person has had chickenpox, the virus remains unnoticed in the body (in the dorsal nerve ganglia) for the rest of their life. The virus can be reactivated, particularly at an advanced age and in immunocompromised people, in the form of shingles (herpes zoster). In this condition a rash and blisters form in a defined area on one side of the body. Various complications can occur: The rash is occasionally accompanied by severe, persistent pain and, in 10-20 % of cases, one eye is affected by the rash.

Occurrence and frequency

Varicella zoster viruses occur throughout the world.

Chickenpox occurs year-round in Switzerland. Practically the entire adult population (98 %) has antibodies to the virus, i.e. most people had chickenpox during their childhood.

Of those who do not catch chickenpox until they are 16 or older, every year, approx. 50 need to be hospitalised for complications, and roughly 20 in every 100,000 of the over-16s die of the disease, i.e. approx. 10 to 20 times more commonly than in children.

About 20 % of people who are infected with VZV, will eventually develop shingles later in life.


Due to the elevated risk of complications in adults, VZV infection should be prevented in anyone who did not have chickenpox as a child. Vaccination against chickenpox (varicella) is therefore recommended for all adolescents between 11 and 15 years of age who are not immune (catch-up vaccination for adults up to the age of 39). Vaccination requires two doses at least four weeks apart. IgG antibodies can be determined to establish a person’s immune status if it is uncertain whether they have already had a VZV infection and chickenpox.

Immunisation against herpes zoster (shingles) with the vaccine Zostavax® is recommended in Switzerland since the end of 2017 for persons aged 65 to 79 years and for patients aged 50 to 79 years who will be immunocompromised in the near future. However, it is currently not reimbursed by mandatory basic health insurance.


Further relevant documents are available in German and French.

Further information

Publications on communicable diseases

Have questions about vaccinations? Need a vaccination record? Looking for information about communicable diseases? You’ll find answers in our publications.

Last modification 12.10.2021

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