New Japanese encephalitis vaccines: alternatives to production in mouse brain

Abstract

Japanese encephalitis virus (JEV), a flavivirus maintained in a zoonotic cycle and transmitted by the mosquito Culex tritaeniorhynchus, causes epidemics of encephalitis throughout much of Asia. Resident populations, including short- or long-term visitors to enzootic regions, are at risk of infection and disease. For the past several decades, killed viral vaccines prepared in tissue culture or mouse brain have been used effectively to immunize travelers and residents of enzootic countries. Cost, efficacy and safety concerns led to the development of a live-attenuated virus vaccine (SA14-14-2) and more recently, to the licensure in the USA, Europe, Canada, and Australia of a purified inactivated, tissue culture-based Japanese encephalitis vaccine (IXIARO^®, referred to as IC51; Intercell AG, Vienna, Austria). In addition, a live-attenuated yellow fever–Japanese encephalitis chimeric vaccine (IMOJEV™, referred to as Japanese encephalitis-CV; Sanofi Pasteur, Lyon, France) was recently licensed in Australia and is under review in Thailand. A broad portfolio of safe and effective Japanese encephalitis vaccines has become available to meet the needs of at-risk populations; when appropriately delivered, these new vaccines should greatly diminish the burden of disease.

Keywords::

• clinical features
• epidemiology
• flavivirus
• Japanese encephalitis
• vaccines

Disclaimer

The opinions or assertions contained herein are the private views of the author Stephen J Thomas and are not to be construed as reflecting the official views of the US Army or the US Department of Defense.

Financial & competing interests disclosure

Stephen J Thomas was an associate investigator on a clinical trial evaluating the JE-PIV (IC51, IXIARO^®) vaccine. This statement is made in the interest of full disclosure and not because the authors consider this to be a conflict of interest. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.