Chickenpox - Treatments

Vaccine (to prevent chickenpox)

Having a vaccine can stop you getting chickenpox. The chickenpox vaccine is made from very weak chickenpox viruses. Its brand names are Varilrix and Varivax.[1] After having an injection of the vaccine, your immune system makes antibodies to fight the weak virus. Your body remembers how to fight the virus in the future. So if you come into contact with the virus again, you fight it off without getting ill.

In the UK, the chickenpox vaccine is recommended only for:[2]

• Health care workers
• People in contact with someone with a weak immune system (for example, someone who has a sister or brother with leukaemia).

You won't need a vaccine if you've already had chickenpox, because you'll have built up an immunity to the virus. You can have a blood test to see if you're immune to chickenpox.[2]

The vaccine isn't recommended for:

• Healthy children
• Pregnant women
• People with a weak immune system (such as people having chemotherapy for cancer, or people with AIDS).

The chickenpox vaccine may cause soreness and redness at the point where you are injected. You may also get a mild rash.

Two studies of healthy children found that having the chickenpox vaccine prevented chickenpox.[3] These studies included more than 1,000 children.[4] [5] [6]

Another small study looked at giving the vaccine within three days to brothers and sisters of a child who has chickenpox. The vaccine didn't stop the brothers and sisters getting chickenpox. But the illness was usually milder in those who had the vaccine.[7]

There haven't been any studies about whether the vaccine stops adults getting chickenpox.

A few children get a high temperature after their vaccination.[8] It's possible for a high temperature to trigger a seizure in children. But the number of children who got a seizure in studies was less than 1 in 1,000. And doctors don't know if the chickenpox vaccine caused the seizures. They could have been caused by another illness, or other vaccines the children had at the same time.[8] [9]

There's also a very small chance your child could spread chickenpox to someone else after having the vaccine.[8]

Aciclovir

If you take aciclovir very soon after getting chickenpox, the illness will probably be milder.

Aciclovir is a medicine that fights viruses. Its brand name is Zovirax. It comes as tablets, as a liquid and as a drip (sometimes called an intravenous infusion or IV).[10]

In the UK, aciclovir isn't usually prescribed for healthy children who get chickenpox because they will get better without any treatment.

The Royal College of Obstetricians and Gynaecologists recommends aciclovir for:

• Women who get chickenpox in the second half of their pregnancy, but only if they start to take it within a day of getting the rash[11]
• New babies who get chickenpox.[11]

Aciclovir can also be given to adults who get chickenpox.

One review of 1,000 healthy children found that taking aciclovir tablets within a day of getting chickenpox reduced how long they had a fever by about a day.[12] But it didn't help with the rash.

Another review of 300 adults found that taking aciclovir within a day of getting chickenpox helped to make the rash less severe.[13] Aciclovir didn't help people who took it on the second or third day.

One review of about 2,000 people with HIV found that those who took a high dose of aciclovir for up to about two years were less likely to get chickenpox or die during this time.[14]

Two studies looked at children with cancer who had chickenpox while they were having chemotherapy.[15] [16] One of the studies found that children who had a drip (an intravenous infusion) of aciclovir got less ill than children who took a dummy treatment (a placebo).[15] The second small study found that aciclovir didn't help.[16]

We don't know whether aciclovir can help people with other types of weak immune systems or newborn babies whose mothers had chickenpox while pregnant. There's not enough good research to tell us.

Aciclovir can cause diarrhoea and make you feel sick.[10]

Injections that contain antibodies (to prevent chickenpox)

Injections that contain antibodies may help fight chickenpox. They aren't used to treat chickenpox once you have it, but they can be used for certain people who haven't had chickenpox but have come into contact with it. These injections are made from other people's blood.

• Zoster immune globulin (ZIG) contains antibodies to the chickenpox virus. It is made from the blood of people who are recovering from shingles.
• Varicella zoster immune globulin (VZIG) is made from blood that has a lot of antibodies to the chickenpox virus.
• Immune serum globulin (ISG) contains many different types of antibodies.

In the UK, varicella zoster immune globulin (VZIG) is sometimes used to treat people who've come into contact with chickenpox in the past 10 days. The injection is put into a muscle. It's used for people who haven't had chickenpox before, so they haven't built up an immunity to the virus. You can have a blood test to see if you're immune to chickenpox.

The people who may need VZIG are:

• Pregnant women[11]
• Newborn babies whose mothers might have had chickenpox when they were born[11]
• People with a weak immune system.[17]

An injection of VZIG can cause redness and swelling at the place where you have the injection.[18]

There isn't much research about using these injections to prevent chickenpox.

One study looked at about 200 children, most of whom had leukaemia. The children took either ZIG or VZIG after coming into contact with chickenpox through a brother or sister. Three months after getting either ZIG or VZIG, about 4 in 10 children had got chickenpox.[19]

One other small study, with only 12 children, looked at using either ISG or ZIG for healthy children who had a brother or sister with chickenpox. It found that ZIG helped prevent chickenpox better than ISG.[20]

There aren't any good studies about using these kinds of injections to prevent chickenpox in other people with a weak immune system, in pregnant women, or in newborn babies whose mothers got chickenpox while pregnant.