# Revolutionary Eilat-based Chikungunya Vaccine Vector

> **NIH NIH R01** · UNIVERSITY OF TEXAS MED BR GALVESTON · 2021 · $825,842

## Abstract

ABSTRACT
Traditionally, viral vaccines have involved trade-offs between safety and immunogenicity, which is especially
challenging for vaccines needed to control explosive emerging diseases where rapid protection and durable
immunity are crucial. To overcome these challenges, we developed a mosquito-specific alphavirus, Eilat virus
(EILV), as a revolutionary new vaccine vector. Eilat replicates to exceptionally high titers in mosquito cells but
is completely defective for replication in vertebrate cells due to fundamental restrictions in entry and RNA
replication. We generated a chimeric EILV cDNA with envelope proteins derived from chikungunya virus
(CHIKV), which is responsible for major reemerging outbreaks of debilitating, chronic arthralgia involving
millions of persons and recently affecting nearly all countries in the Americas. A CHIKV vaccine was recently
ranked the #2 priority for global vaccine needs. In preliminary studies, the chimeric EILV/CHIKV vaccine
candidate provided rapid and durable protection following a single dose against challenge of mice and
nonhuman primates. We will further develop this chimera and test the hypothesis that EILV-based chimeric
viruses can serve as “pseudoinactivated” alphavirus vaccines, using three Aims:
1. Optimize the replication and immunogenicity of the chimeric EILV/CHIKV vaccine, confirm its safety
 (including unambiguously demonstrating a lack of RNA replication in vertebrate cells), verify efficient
 production in serum-free media, and develop inexpensive purification methods.
2. Study the protective efficacy of the optimized EILV/CHIKV vaccine in mice and understand the immune
 mechanisms of host protection, including characterization of innate and adaptive immune responses in
 vaccinated and challenged mice, and determination of the immune correlates of host protection.
3. Optimize the dosage of the EILV/CHIKV vaccine and confirm its rapid and long-lived immunogenicity and
 protection in cynomolgus macaques. These outcomes will be compared to inactivated and live-attenuated
 CHIKV vaccines.
The result will be a safe, efficacious, inexpensive single-dose CHIKV vaccine that provides rapid and long-lived
protection, as well as a platform technology that can be applied to all other pathogenic alphaviruses such as
Venezuelan and Eastern equine encephalitis viruses, and the recently emerging Mayaro virus. These vaccines
will be ideally suited for controlling explosive outbreaks that typically affect resource-poor tropical countries.
The mechanistic studies to understand the remarkable immunogenicity of this vaccine will also impact other
vaccine design platforms by dissecting the fundamental components of a viral vaccine required to induce
various arms of the protective immune response.

## Key facts

- **NIH application ID:** 10176378
- **Project number:** 5R01AI127744-05
- **Recipient organization:** UNIVERSITY OF TEXAS MED BR GALVESTON
- **Principal Investigator:** Tian Wang
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $825,842
- **Award type:** 5
- **Project period:** 2017-06-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10176378

## Citation

> US National Institutes of Health, RePORTER application 10176378, Revolutionary Eilat-based Chikungunya Vaccine Vector (5R01AI127744-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10176378. Licensed CC0.

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