“I think it’s really important that people keep signing up to these type of trials to push research forward.”
A study looking at a vaccine to prevent infection in children with acute lymphoblastic leukaemia
This study was done to find out the best time to give Prevenar-13 to help prevent infections. It was for children with acute lymphoblastic leukaemia (ALL) who were having or had recently finished treatment.
The study was open for people to join between 2010 and 2014. The team published results in 2020.
More about this trial
Our immune system helps us fight infections. Chemotherapy can weaken the immune system. This means people having chemotherapy are more likely to get an infection.
Doctors know that children who have chemotherapy for ALL have an increased risk of an infection called pneumococcus. This can be the case for months after they finish treatment. So they have a vaccine to help prevent this infection.
When this study was done, children in the UK often had the vaccine about 6 months after they finished treatment. But this was different in other countries. And the researchers wanted to find out the best time to give it.
In this study the researchers looked at a vaccine called Prevenar-13 (PCV13). The children who took part had the vaccine either:
- during the last few months of chemotherapy
- a month after they finished chemotherapy
- 6 months after they finished chemotherapy
The research team measured the number of various immune system cells to see if they changed. And how long the changes lasted.
The main aim of this study was to find out the best time to give Prevenar-13 to help prevent pneumococcal infection in children with ALL.
Summary of results
The research team found that it is best to give the vaccine soon after finishing chemotherapy.
The children in this study had acute lymphoblastic leukaemia (ALL). Some were coming to the end of their planned treatment. Some had recently finished treatment.
The research team took blood samples to measure different immune system cells:
- before they had the vaccine
- 4 weeks after they had the vaccine
- a year after they had the vaccine
A total of 118 children aged between 2 and 17 joined this study:
- 39 had the vaccine during treatment
- 40 had the vaccine soon after finishing treatment
- 39 had the vaccine 6 months after finishing treatment
The research team measured the immune cells in blood samples before and after the vaccine injection.
The results were similar for:
- those who had the injection soon after treatment, and
- those who had the injection 6 months after treatment
They found that the immune system had responded to the vaccine 1 month after the injection in:
- 5 out of 39 children (13%) who had the vaccine during treatment
- 22 out of 37 children (59%) who had the vaccine soon after treatment
- 21 out of 37 children (57%) who had the vaccine 6 months after treatment
And that the immune system response was still there a year after the injection in:
- no one who had the vaccine during treatment
- 11 out of 29 children (38%) who had the vaccine soon after treatment
- 13 out of 30 children (43%) who had the vaccine 6 months after treatment
They also looked at levels of different immune cells in more detail. This showed that the levels of some immune cells fell during treatment and stayed low for months afterwards. But the levels of other immune cells fell during treatment and went back to normal quite quickly.
The research team concluded that it is best to give the Prevenar-13 vaccine to children soon after they finish treatment. They suggest that UK guidelines are updated to recommend this.
Where this information comes from
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
Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.
Dr Juliet Gray
NIHR Clinical Research Network: Cancer
NIHR Research for Patient Benefit (RfPB) Programme
University Hospital Southampton NHS Foundation Trust
If you have questions about the trial please contact our cancer information nurses
Freephone 0808 800 4040