Experience with the live Oka-strain varicella vaccine in children with solid tumours.

A comparative evaluation of radioimmunoassay (RIA), indirect immunofluorescence, fluorescent antibody to membrane antigen, competitive inhibition RIA, and complement fixation methods for determining the immune status to varicella-zoster virus (VZV) showed that RIA was the most sensitive test. However, this test is still not regarded as being entirely satisfactory and possible reasons are discussed. To date, 28 children, mainly with solid tumours, have been inoculated with the Oka-strain live varicella vaccine. Two of these vaccinees developed minor reactions, but only 62% developed a RIA-detectable humoral response. Approximately 46% of the responders had lost induced antibody within 12 months of vaccination. None of the 6 vaccinees that have subsequently been in contact with varicella developed any illness suggesting that they had been protected.