Although it’s not usually dangerous, chickenpox can be very unpleasant as it causes an itchy rash and a fever. In most cases, the symptoms clear within a week.

The virus can be dangerous for patients with an impaired immune system, newborn babies and pregnant women. Once you have had chickenpox, you’re usually immune for life but you could develop shingles at a later point in life.

The chickenpox vaccine is not currently part of the national vaccine schedule in the UK but it has been given routinely in a number of countries around the world, such as the USA and Germany.

It belongs to a group of vaccines referred to as “live” vaccines. This means, that it contains a weakened version of the virus that causes chickenpox. The vaccine causes your immune system to react to the vaccine. As a result, you’ll be immune to it if you catch the virus at a later date.

It does not protect against similar viruses, such as the herpes virus. It also doesn’t protect against shingles. In order to prevent shingles, you can get a shingles vaccination.

You need two doses to be protected and the second dose should be given at least four but no later than eight weeks after you have received your initial dose. Once you have completed the course, you won’t need further boosters.

If you have been exposed to the chickenpox virus the vaccine will still prevent it if you get vaccinated within three days of exposure.

It is also possible that it will cause a mild rash – one in ten children and one in ten adults who receive the vaccine experience this side effect. This rash is not contagious and it should pass quickly.

The only serious known side effect is an allergic reaction to the vaccine. Allergic reactions to the chickenpox vaccine are extremely rare and believed to affect around one in a million patients who receive the vaccine.

The chickenpox vaccine is safe and has been given several million times around the world. There are no known long-term side effects.

You can’t have the chickenpox vaccine if you have previously had an allergic reaction to any of the ingredients in the vaccine.

The vaccine is not suitable for pregnant women or women who are trying for a baby. After receiving the vaccine, you need to use contraception for at least four weeks. The vaccine is not recommended for breastfeeding women.

If you are ill on the day of your vaccination you may need to reschedule your appointment.

Getting a flu vaccine too? The flu vaccine does not interfere with the chickenpox vaccine so you can have these at the same time or at any time interval.

However, if it is unclear whether or not your child has had chickenpox, they can still be vaccinated as this can prevent future disease and it is unlikely to cause any harm even if they have had chickenpox before.

Chickenpox is transmitted directly by close contact or droplet spread and it can take several days for symptoms to develop. If you believe your child has been exposed to chickenpox and is not showing any symptoms, they may still have the vaccine.

Vaccination within 3 days of exposure may help prevent chickenpox or reduce the severity of disease, resulting in fewer skin lesions and a shorter period of illness. However, there is limited information that being vaccinated up to 5 days after exposure may reduce disease severity.