vaccines have been approved to be administered in parts of the world. The Ad5-

nCOV developed by CanSino Biologics Inc. and Beijing Institute of Biotechnology

used a HAd5 as the vector [38]. In Europe, Janssen Vaccines & Prevention B.V.

(Johnson & Johnson) developed Ad26.COV2-S vaccine with a rare HAd26

vector [41]. Gamaleya Research Institute in Russia used a combination of HAd5

and HAd26 to develop Gam-COVID-Vac/SputnikV vaccine [25]. The University of

Oxford collaborated with AstraZeneca to develop ChAdOX1-nCoV based on a

chimpanzee (ChAdY25) vector [43].

11.3

VESICULAR STOMATITIS VIRUS (VSV) VECTORED VACCINES

11.3.1

VESICULAR STOMATITIS VIRUS

Vesicular stomatitis virus (VSV) is a member of the Rhabdoviridae family in the

Vesiculovirus genus [62]. Vesiculovirus genus members are widely distributed in

nature and mainly infect biting insects and livestock. According to the geographic

distribution, at least 14 different phylogenetical and serological members in the

Vesiculovirus genus are divided into two groups [63]. One includes the Indiana (IND)

and New Jersey (NJ) serotypes of VSV, which were found in the Americas. The other

was found in the Eastern Hemisphere including Chandipura, Yug Bogdanovac, and

Isfahan [62]. The symptom of VSV infection of livestock is transient and accom-

panied by low level of viremia without a major virus spread. There are rare cases that

VSV infects humans, but only when they are exposed to VSV in laboratories or when

they come in close contact with the infected animals. Humans can be infected through

skin and mucous tissues, while some cases are reported to be infected by insect bites.

Human infection by VSV can be accompanied with disease symptoms including

myalgia, fever, and headache, which resolve within days [64].

The standard VSV particle is a bullet-shaped, single-strand, negative-sense RNA

virus with 65 × 180 nm. The viral genome is about 11 kilobases, which encodes five

major viral proteins including nucleoprotein (N), phosphoprotein (P), matrix

protein (M), glycoprotein (G), and the viral polymerase (L) [65]. The N protein as-

sociates to form viral nucleocapsid for genomic RNA, which serves as functional

template for viral replication and transcription. This protein is also the most abundant

protein expressed in infected cells. The M protein is the main protein in the VSV

particle. The M protein has various functions in infected cells. This protein can

regulate the viral transcription, inhibit the gene expression of host cells, and contribute

to virus budding. The P and L genomic motifs associate to express the viral RNA

polymerase with the functions of transcriptase and replicase. The G protein is a

transmembrane glycoprotein on the virus surface with a trimeric spike-like structure.

The G protein is responsible for virus attachment to the receptors of host cells.

11.3.2

CONSTRUCTION AND PRODUCTION PROCESS OF VSV VECTORS

11.3.2.1

Pseudotype and Recombinant VSV

VSV is widely used as a viral vector in various fields including vaccines, gene

therapy, and oncolytic virotherapy. Most virus-based vectors with envelopes are

Vectored vaccines

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