# Venezuelan equine encephalitis virus: novel live-attenuated vaccines for inducing complete protective immunity

**Authors:** Kenneth C. Elliott, David Saunders, Joseph J. Mattapallil

PMC · DOI: 10.1038/s44298-026-00186-5 · npj Viruses · 2026-03-21

## TL;DR

This paper discusses the development of new live-attenuated vaccines for Venezuelan equine encephalitis virus to improve safety and effectiveness over existing options.

## Contribution

The paper introduces novel live-attenuated VEEV vaccine candidates currently in clinical development.

## Key findings

- VEEV can cause severe disease and has high mortality when aerosolized.
- Current vaccines like TC-83 have safety and immunogenicity issues.
- New vaccine candidates like V4020 and V3526 show promise in preclinical and clinical studies.

## Abstract

Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne alphavirus that causes severe neuroinflammation and fatal infections in some people. Numerous outbreaks of VEEV have been reported in Latin America in the past century. Though mosquito-borne, studies have demonstrated that aerosolized VEEV infections lead to significantly higher mortality rates in animal models, suggesting that VEEV, if aerosolized, could cause widespread infections. There are currently no FDA-approved vaccines against VEEV, though TC-83, a live-attenuated strain of VEEV, has been tested as an investigational new drug in laboratory personnel and at-risk health workers. Its use, however, has been associated with severe adverse events and variable immunogenicity. Novel live-attenuated vaccines such as the V4020, V3526, VRC-WEVVLP03-00VP, 68U201/IRES1, and others are under development to overcome some of the limitations associated with the TC-83 vaccine. Here, we discuss the pathogenesis of VEEV and the current state of VEEV vaccines that are in clinical development.

## Linked entities

- **Diseases:** Venezuelan equine encephalitis (MONDO:0006005)

## Full-text entities

- **Genes:** ERF (ETS2 repressor factor) [NCBI Gene 2077] {aka CHYTS, CRS4, PE-2, PE2}, SH2D3A (SH2 domain containing 3A) [NCBI Gene 10045] {aka NSP1}, APP (amyloid beta precursor protein) [NCBI Gene 351] {aka AAA, ABETA, ABPP, AD1, APPI, CTFgamma}, PTGES3 (prostaglandin E synthase 3) [NCBI Gene 10728] {aka P23, TEBP, cPGES}, TRBV20OR9-2 (T cell receptor beta variable 20/OR9-2 (non-functional)) [NCBI Gene 6962] {aka CDR3, TCRBV20S2, TCRBV2O, TCRBV2S2O}, FURIN (furin, paired basic amino acid cleaving enzyme) [NCBI Gene 5045] {aka FUR, PACE, PCSK3, SPC1}, CD8A (CD8 subunit alpha) [NCBI Gene 925] {aka CD8, CD8alpha, IMD116, Leu2, p32}, ERVK-20 (endogenous retrovirus group K member 20) [NCBI Gene 100616444] {aka c11_B, env}, CD4 (CD4 molecule) [NCBI Gene 920] {aka CD4mut, IMD79, Leu-3, OKT4D, T4}, LDLRAD3 (low density lipoprotein receptor class A domain containing 3) [NCBI Gene 143458] {aka LRAD3}, IFIT1 (interferon induced protein with tetratricopeptide repeats 1) [NCBI Gene 3434] {aka C56, G10P1, IFI-56, IFI-56K, IFI56, IFIT-1}, TRD (T cell receptor delta locus) [NCBI Gene 6964] {aka TCRD, TCRDV1, TRD@}
- **Diseases:** leucopenia (MESH:C536227), mouth ulcers (MESH:D019226), blindness (MESH:D001766), confusion (MESH:D003221), myalgia (MESH:D063806), chills (MESH:D023341), meningitis (MESH:D008580), gait abnormalities (MESH:D020233), sore throat (MESH:D010612), diarrhea (MESH:D003967), febrile illness (MESH:D005334), stupor (MESH:D053608), reduced appetite (MESH:D001068), ID (MESH:C537985), anorexia (MESH:D000855), dengue (MESH:D003715), edema (MESH:D004487), coma (MESH:D003128), vomiting (MESH:D014839), convulsions (MESH:D012640), inflammation (MESH:D007249), hallucinations (MESH:D006212), ulcers (MESH:D014456), Infection (MESH:D007239), encephalitis (MESH:D004660), hemorrhage (MESH:D006470), nausea (MESH:D009325), febrile disease (MESH:D004194), abnormal chewing movements (MESH:D004409), viral encephalitis (MESH:D018792), death (MESH:D003643), depression (MESH:D003866), leukopenia (MESH:D007970), viremia (MESH:D014766), congestion (MESH:D002311), neuroinflammation (MESH:D000090862), headache (MESH:D006261), CNS infections (MESH:D002494), abortions (MESH:D000026), hemiparesis (MESH:D010291), vasculitis (MESH:D014657), CNS lesions (MESH:D002493)
- **Chemicals:** formalin (MESH:D005557), TC-83 (-), ND (MESH:D009354)
- **Species:** Equus caballus (domestic horse, species) [taxon 9796], Oryctolagus cuniculus (domestic rabbit, species) [taxon 9986], Equus asinus (African ass, species) [taxon 9793], Venezuelan equine encephalitis virus (no rank) [taxon 11036], Mucambo virus (no rank) [taxon 60875], Cricetinae (hamsters, subfamily) [taxon 10026], Western equine encephalitis virus (no rank) [taxon 11039], Eastern equine encephalitis virus (no rank) [taxon 11021], Mus musculus (house mouse, species) [taxon 10090], Sagamiharavirus PP (species) [taxon 2956385], Sigmodon (cotton rats, genus) [taxon 42414], Sindbis virus (no rank) [taxon 11034], Macaca (macaque, genus) [taxon 9539], Cabassou virus (no rank) [taxon 60879], Everglades virus (no rank) [taxon 2083198], Cavia porcellus (domestic guinea pig, species) [taxon 10141], Homo sapiens (human, species) [taxon 9606], Rio Negro virus (no rank) [taxon 332097], Psorophora columbiae (species) [taxon 869070], Tonate virus (no rank) [taxon 60877], Chikungunya virus (no rank) [taxon 37124], Ochlerotatus taeniorhynchus (species) [taxon 329105], Pixuna virus (no rank) [taxon 60876]
- **Mutations:** guanine (G) to adenine (A) residue at position 3, Arg at position 213, CGA instead of ACA, threonine to arginine at position 120

## Full text

_Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/PMC13004899/full.md

## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/PMC13004899/full.md

## References

10 references — full list in the complete paper: https://tomesphere.com/paper/PMC13004899/full.md

---
Source: https://tomesphere.com/paper/PMC13004899