¹Karolinska University Hospital, Stockholm, Sweden

Correspondence: Dr P Ljungman, Department of Hematology, Karolinska University Hospital, Stockholm 14186, Sweden. E-mail: Per.Ljungman@medhs.ki.se

Received 17 May 2004; Accepted 14 July 2004; Published online 18 October 2004.

Abstract

Revaccination with poliovirus after allogeneic stem cell transplant (SCT) is usually effective, but the longevity of this immunity is unknown. Therefore, poliovirus immunity was studied in 134 patients having survived at least 5 years after vaccination. The median follow-up from vaccination was 8 years (1–19 years). In all, 21 (15.6%) patients had become seronegative to at least one of the poliovirus serotypes during follow-up. The estimated probabilities of remaining immune to poliovirus at 5 and 10 years after vaccination were 94 and 94% for subtype 1, 98 and 94% for subtype 2, and 93 and 90% for subtype 3, respectively. In multivariate analysis, the only risk factor for loss of immunity was younger patient age (P<0.01), and there was a strong trend for patients with chronic GVHD to lose immunity more rapidly (P=0.07). A total of 14 patients received a booster dose of an inactivated poliovirus vaccine and all responded. We conclude that poliovirus immunity is retained long term after revaccination in most patients after allogeneic SCT.