No bad effects have been seen in animal studies using the special virus markers or in more 
than 30 people treated with these markers, but it is possible that the special virus may grow 
or stop some antibiotics from working or even cause cancer. We do not think this will 
happen, but it is possible. 
ALTERNATIVE PROCEDURES 
You/your child can have no extra treatment at all, but we believe that this extra treatment 
will reduce your risk of infection with EBV after your/your child's transplant. 
STATEMENT OF UNDERSTANDING 
All information about your/your child's treatment will be kept among the hospital staff that 
needs to know. We will not tell anybody else without asking you first. You/your child have 
the right to ask any questions you/your child want and they will be answered. You/your 
child have had this assent form read or discussed with you by your parents and the doctor 
(Dr. ) caring for you/your child. Before you signed this form you had 
all your questions answered. 
If you have any other questions you can ask your doctor or Dr. Helen Heslop or 
Dr. Malcolm Brenner at any time. 
Patient 
Parent or Guardian 
Physician 
Date and Time 
Recombinant DNA Research, Volume 17 
[223] 
