Journal Article

A Japanese Encephalitis Vaccine From India Induces Durable and Cross-protective Immunity Against Temporally and Spatially Wide-ranging Global Field Strains

Singh, Anit, Gopinathan, K., Rao, N. Bhuvaneswara, Sudhakar, B., Gore, Milind M., Ella, Krishna M., Gupta, Mukesh Kumar, Mohan, V. Krishna, Venugopal, P., Krishnamurthy, B., Krishna, S. Sri, Hegde, Nagendra R., Sampath, Gadey, Kaushik, Yashpal, Rao, J. Venkateswara, Mitra, Monjori

2015

Overview

Background. Japanese encephalitis (JE) is a vaccine-preventable acute disease. We report the results of a phase 2/3 trial of JENVAC, a Vero cell-derived vaccine developed using an Indian strain of JE virus (JEV). Methods. JENVAC was administered in 2 doses 28 days apart, and immunogenicity was compared to that from a single dose of SA-14-14-2, the only approved JE vaccine and regimen at the time in India. Results. After both the doses, seroconversion and seroprotection were >90% for JENVAC. For SA-14-14-2, seroconversion and seroprotection were 57.69% and 77.56%, respectively, on day 28 and 39.74% and 60.26%, respectively, on day 56. The geometric mean titers at day 28 and day 56 were 145.04 and 460.53, respectively, for JENVAC and 38.56 and 25.29, respectively, for SA-14-14-2. With a single dose of JENVAC, seroprotection titers lasted at least 12 months in >80% of the subjects. Following receipt of 2 doses, 61.17% of subjects retained seroprotection titers at 24 months, and immunogenicity criteria were higher than that for SA-14-14-2 at 12, 18, and 24 months each. Sera from JENVAC subjects neutralized JEV genotypes I, II, III, and IV equally well. Adverse events were not significantly different between the 2 vaccines. Conclusions. JENVAC elicits long-lasting, broadly protective immunity. Clinical Trials Registration. CTRI/2011/07/001855.

• Publisher: Oxford University Press
• Subject: Adolescent / Adult / Antibodies, Neutralizing - blood / Antibodies, Viral - blood / Child / Child, Preschool / Cross Reactions / Drug-Related Side Effects and Adverse Reactions - epidemiology / Drug-Related Side Effects and Adverse Reactions - pathology / Encephalitis Virus, Japanese - classification / Encephalitis Virus, Japanese - genetics / Encephalitis Virus, Japanese - immunology / Female / Humans / Immunity, Heterologous / India / Infant / Japanese Encephalitis Vaccines - administration & dosage / Japanese Encephalitis Vaccines - immunology / Male / Middle Aged / Molecular Sequence Data / RNA, Viral - genetics / Sequence Analysis, DNA / Vaccination - methods / VIRUSES / Young Adult