Vaccination against Japanese encephalitis with IC51: systematic review on immunogenicity, duration of protection and safety
- 10 February 2020
- journal article
- review article
- Published by Oxford University Press (OUP) in Journal of Travel Medicine
- Vol. 27 (2)
- https://doi.org/10.1093/jtm/taaa016
Abstract
Japanese encephalitis is a disease caused by a flavivirus which is transmitted by mosquitos in endemic countries. Considering the potentially severe outcomes of the disease, vaccination is recommended for those at risk of exposure. During recent years, IC51 (IXIARO®, JESPECT®, JEVAL®) has increasingly been used to protect travelers from Europe and the US. However, no systematic review exists that summarizes the currently available evidence on the immunogenicity and safety of this vaccine. We conducted a systematic review on the immunogenicity and safety of IC51, using the databases PubMed, MEDLINE, EMBASE and ClinicalTrials.gov (search date: 31 August 2019). Data extracted from included studies were grouped by outcomes and stratified by population and setting. Risk of bias (ROB) was assessed using the RoB 2 tool for randomized controlled trials (RCTs) and ROBINS-I for non-randomized studies. Due to high heterogeneity, meta-analysis was not performed. A total of 32 studies from 16 countries met the inclusion criteria (15 RCTs, 17 non-randomized studies). ROB was serious or high in the majority of studies. Seroprotection rates ranged from 93% to 100% in adults (seven studies), and from 91% to 100% in children (four studies). In the study involving adults aged 64 years and older, seroprotection was 65% with higher rates in persons who were previously vaccinated against tick-borne-encephalitis-virus. Safety was investigated in 27 studies. Rates of serious adverse events were below 5% in all age-groups, with the majority not being causally related to the vaccine. IC51 is a safe vaccine with good seroprotective abilities in persons aged > 2 months to < 64 years. The body of evidence, however, is weakened by a large amount of heterogeneity in study and clinical trial methodology. Further well-designed RCTs with special risk groups are needed.Keywords
This publication has 54 references indexed in Scilit:
- Envelope protein gene based molecular characterization of Japanese encephalitis virus clinical isolates from West Bengal, India: a comparative approach with respect to SA14-14-2 live attenuated vaccine strainBMC Infectious Diseases, 2013
- Recurrence of Japanese Encephalitis Epidemic in Wuhan, China, 2009–2010PLOS ONE, 2013
- Effectiveness of the Viet Nam Produced, Mouse Brain-Derived, Inactivated Japanese Encephalitis Vaccine in Northern Viet NamPLoS Neglected Tropical Diseases, 2012
- Cross-Protective Capacity of Japanese Encephalitis (JE) Vaccines Against Circulating Heterologous JE Virus GenotypesClinical Infectious Diseases, 2012
- A Single Dose of Vero Cell-Derived Japanese Encephalitis (JE) Vaccine (Ixiaro) Effectively Boosts Immunity in Travelers Primed With Mouse Brain-Derived JE VaccinesClinical Infectious Diseases, 2012
- The Cochrane Collaboration's tool for assessing risk of bias in randomised trialsBMJ, 2011
- Correlation of protection against Japanese encephalitis virus and JE vaccine (IXIARO®) induced neutralizing antibody titersVaccine, 2011
- Isolation and Genetic Characteristics of Human Genotype 1 Japanese Encephalitis Virus, China, 2009PLOS ONE, 2011
- Long-term immunity and immune response to a booster dose following vaccination with the inactivated Japanese encephalitis vaccine IXIARO®, IC51Vaccine, 2010
- Japanese Encephalitis Vaccine (Inactivated, Adsorbed) [IXIARO®]Drugs, 2009