Safety and Immunogenicity of High Dose Trivalent Inactivated Influenza Vaccine in Pediatric Patients with Acute Lymphoblastic Leukemia

McManus, Meghann; Frangoul, Haydar; McCullers, Jonathan A.; Wang, Li; O'Shea, Alice; Halasa, Natasha

BACKGROUND: Although children with acute lymphoblastic leukemia (ALL) mount immune responses after vaccination with the trivalent influenza vaccine (TIV), these responses are lower compared to controls. Recently, a high dose (HD) TIV was found to increase the level of antibody response in elderly patients compared to the standard dose (SD) TIV. We hypothesized that the HD TIV would be well-tolerated and more immunogenic compared to the SD TIV in pediatric subjects with ALL. PROCEDURE: This was a randomized, double-blind, phase I safety and immunogenicity trial comparing the HD to the SD TIV in children with ALL. Subjects were randomized 2:1 to receive either the HD (60µg) or the SD (15µg) TIV. Local and systemic reactions were solicited, hemagglutinin inhibition titers to influenza virus antigens were measured, and monitoring labs were collected prior to and/or after each vaccination. RESULTS: Fifty subjects were enrolled (34 HD, 16 SD). Mean age was 8.5 years; 63% were male, and 80% were in maintenance therapy. There were no significant differences reported in local or systemic symptoms. No severe adverse events were attributed to vaccination. No significant differences between the HD and SD TIV groups were noted for immune responses. CONCLUSIONS: No differences were noted between the HD and SD TIV groups for solicited systemic and local reactions. Since this study was not powered for immunogenicity, a phase II trial is needed to determine the immunogenicity of HD versus SD TIV in the pediatric ALL population.