1241. PfSPZ Vaccine Administered by Direct Venous Inoculation to Prevent Plasmodium falciparum Malaria is as Safe as Normal Saline – a Meta-analysis of 12 Randomized Controlled Clinical Trials

Abstract

BackgroundSanaria’s PfSPZ Vaccine prevents Plasmodium falciparum (Pf) infection transmitted in the field and by controlled human malaria infection. Safety of PfSPZ Vaccine has been demonstrated in 12 randomized, double-blind, placebo-controlled trials (RCT) varying in regimen from 3 to 5 doses over 4 to 20 weeks and in size from 18 to 332 subjects in adults in the US and EU and 5-month to 65-year-olds in 5 countries in sub-Saharan Africa. This study was conducted to analyze solicited adverse event (AE) and laboratory data by random effects meta-analysis.MethodsPfSPZ Vaccine is composed of radiation-attenuated, aseptic, purified, cryopreserved Pf sporozoites (SPZ) administered by direct venous inoculation (DVI). Normal saline (NS) is always the placebo. Data from all completed RCTs were included as either age > 18 years (n=598) or age 5 months to 17 years (n=641). Any subject receiving at least one dose was included. A random-effects model was used to study vaccine safety and I2 to evaluate heterogeneity. Analysis was performed for any systemic solicited AE and for the most frequently observed AEs and laboratory abnormalities. Sensitivity analyses were performed by removal of trials with zero events to evaluate potential bias.ResultsWhen examined individually, only 1 trial had a significant difference between PfSPZ Vaccine and NS for any AE (myalgias in adults). In the adult meta-analysis, there was no difference in the random effects risk ratios (RR) for having any vaccine-related AEs (1.40, 95% confidence interval (CI) 0.88-2.28), or for fever (0.75, 0.24-2.35), headache (1.23, 0.74-2.02), fatigue (0.72, 0.19-2.54), or myalgia (1.09, 0.26-4.68). In the pediatric meta-analysis there was no difference between the RR for PfSPZ Vaccine and NS for any AE (0.84, 0.59-1.18) or for fever (1.09, 0.44-2.69). No significant differences in the most common grade 2 or higher laboratory abnormalities – declines in hemoglobin, neutrophil or platelet count – were detected. Sensitivity analysis did not change the results.ConclusionThere was no difference in risk for AEs or lab abnormalities between PfSPZ Vaccine and NS, indicating that PfSPZ Vaccine administered by DVI was extremely safe and well tolerated in 5-month- to 65-year-olds.DisclosuresLW Preston Church, MD, FIDSA, Sanaria Inc. (Employee)