"He went through six operations and was placed on a clinical trial so he could try new treatments.”
A study looking at VZIG or aciclovir for children who have been exposed to chicken pox during cancer treatment (PEPtalk2)
This study compared VZIG and aciclovir to prevent chicken pox in children who are exposed to chicken pox during treatment for cancer.
More about this trial
- VZIG - an injection of an antibody to boost immunity
- Aciclovir – syrup or tablets that help prevent viral infections
Summary of results
This pilot study showed that it would be difficult to run a large trial comparing VZIG and aciclovir for children exposed to chicken pox during cancer treatment.
The research team recruited patients in 2014 and 2015, and published the results in 2018.
The research team looked at 482 children who they thought may be able to take part in this trial. But blood test results showed that 337 of them (70%) had already been exposed to chicken pox. And another 47 may have been exposed to it. These children were unable to take part. These numbers were higher than the research team were expecting.
Some families decided they didn’t want to take part. So the research team were able to register 32 of the original 482 children.
Only 3 of these children were exposed to chickenpox during the trial. This was lower than the research team were expecting.
These 3 children were put in 1 of 2 treatment groups at random. This means that neither the doctors or patients decide which group they are in. In this trial, all 3 children were put in to the aciclovir group. This means that there wasn’t anyone in the VZIG group.
No one who had aciclovir went on to develop chicken pox. But the research team were unable to compare this to how well VZIG worked.
No one taking part had any side effects from the aciclovir.
The research team concluded that it was unlikely to be possible to run a large trial comparing aciclovir and VZIG in children having chemotherapy for cancer.
They have identified some parts of the trial design that could be changed. But they suggest researchers look at other ways to decide how best to prevent chicken pox in this group of patients.
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (
How to join a clinical trial
Professor Paul Heath
Cancer Research UK Clinical Trials Unit University of Birmingham
NIHR Clinical Research Network: Cancer
NIHR Research for Patient Benefit (RfPB) Programme
St George's Healthcare NHS Trust
University of Birmingham
Children’s Cancer and Leukaemia Group (CCLG)