Recent developments in vaccines and biological therapies against Japanese encephalitis virus

ABSTRACT

Introduction: Japanese encephalitis is the most common vaccine-preventable encephalitis in the Asia-Pacific region.

Areas covered: We provide an overview on Japanese encephalitis virus and associated disease, review the results of studies on the immunogenicity and efficacy of the licensed vaccines, and describe the new vaccines that are under development. We also discuss data on candidate anti-Japanese encephalitis drugs that have shown promising results in experimental models.

Expert opinion: The global burden of the Japanese encephalitis and associated mortality is still high, thus emphasizing the need to achieve the highest vaccination coverage in endemic areas. Clinical trials exhaustively demonstrated the safety and efficacy of current Japanese encephalitis vaccines. In addition, several new vaccine candidates, characterized by high immunogenicity and broad cross-protection, have been developed and evaluated in experimental models, warranting further clinical testing. No licensed anti-Japanese encephalitis drugs are available, notwithstanding intense research efforts. Some candidate antiviral agents that inhibit viral entry and replication have been identified, including compounds with broad-spectrum antiviral activity. Further research is needed to refine candidate compounds into drugs suitable for clinical evaluation, characterized by low toxicity, ability to penetrate the blood–brain barrier, activity during the late phase of infection, and high genetic barrier to resistance.

KEYWORDS:

• Antiviral agents
• broad-spectrum
• cross-protection
• efficacy
• immunity
• Japanese encephalitis
• safety
• vaccines

Article highlights

• Japanese encephalitis, a mosquito-transmitted viral infection, is the most common vaccine-preventable encephalitis in the Asia-Pacific region.

• Safe and effective Japanese encephalitis vaccines are available, but vaccination coverage in some populations exposed to the risk of infection is still low.

• New vaccine candidates, characterized by high immunogenicity and broad cross-protection, have been developed and evaluated in experimental models.

• No specific anti-Japanese encephalitis drugs have been licensed, but targets for antiviral drug discovery and some candidate antiviral agents have been identified.

• Required features for anti-Japanese encephalitis drugs are low toxicity, ability to penetrate the blood-brain barrier, activity during the late phase of infection, and high genetic barrier to resistance.

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Declaration of interest

The authors have no 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. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was not funded.