Vaccinia Virus (VACV or VV) as Vaccine-vectors

Vaccinia virus (VACV or VV) is the most widely used viral vector for the study of exogenous gene expression and immunogenicity of the resulting protein. Replication-competent recombinant VACV-based vaccines have received increasing attention as potential vaccine vectors for many infectious diseases, as they may be able to elicit potent humoral and cell-mediated immune responses and long-lasting protection. Different approaches have been developed at Creative Biolabs to enhance the immune response in an effort to generate a safe VACV vaccine platform.

Vaccinia Biology

Vaccinia virus is a large and complex enveloped virus, which has a linear, double-stranded DNA genome encoded for around 250 genes. Vaccinia virus is known for its role as a vaccine that eradicated the smallpox disease in the late 1970s, making it the first human disease to be successfully eradicated by humans. After eradicating smallpox, Vaccinia virus has been studied as a tool for delivering genes into biological tissues. Vaccinia virus has been more widely used for human immunization than any other vaccine. Scientists also use the ability of the VACV genome to accommodate other genetic material to produce new vaccines against various infectious agents.

Vaccinia Virus as Vaccine-vectors

With the tremendous experience gained during the eradication of smallpox with vaccinia, vaccinia virus has moved to the forefront in the development of virus vector vaccines. Vaccinia virus can accept up to 25 kb of foreign DNA and can, therefore, be used to express large genes. The foreign genes are stably integrated into the viral genome, resulting in efficient gene expression. Vaccinia viruses re-engineered to express foreign genes are robust vectors for production of recombinant proteins. The vaccinia viruses have been engineered to express immunizing antigens of influenza, hepatitis B, rabies, herpes virus, HIV and other viruses.

Recombinant vaccinia viruses have been produced from different Vaccinia virus strains. Creative Biolabs has developed a variety of highly attenuated, host-restricted, non- or poorly replicating poxvirus strains for use as substrates in recombinant vaccine development, including the Orthopoxviruses, Modified Vaccinia Ankara (MVA), NYVAC, Avipoxviruses, ALVAC, and TROVAC.

Modified Vaccinia Virus Ankara (MVA)

Modified vaccinia virus Ankara (MVA) was derived from Vaccinia strain Ankara through more than 570 blind passages in chicken embryo fibroblasts (CEF). This resulted in vaccinia virus losing about 15% of its genome. With the exception of the Syrian hamster cell line BHK-21, the ability of MVA to replicate in most mammalian primary cells and cell lines has been lost, although genome replication, late-gene expression, and immature virion formation are still able to occur, except in human blood-derived dendritic cells (DC), in which only early viral genes are expressed. This makes MVA an attractive candidate for its use as a vaccine vector to deliver recombinant proteins and induce protective immunity. Recombinant MVA (rMVA) has been used in various preclinical and phase I and phase II clinical trials against a number of tumor-associated antigens and infectious agents, including influenza, measles virus, parainfluenza, plasmodium parasites, and flaviviruses.

NYVAC

The attenuated NYVAC vector was derived from the plaque clone isolate of the Copenhagen Vaccinia vaccine strain by deleting 18 open reading frames (ORFs) from the viral genome, which encode for virulence factors and human host range replication proteins. Highly attenuated vaccinia viruses retain the ability to express foreign genes and produce an immune response in an immune host. The very good safety profile and ability to deliver antigens in a highly immunogenic manner make NYVAC suitable as a vaccine vector. NYVAC is being extensively studied in clinical vaccination trials against a variety of infectious diseases, including HIV.

ALVAC

As an attenuated canarypox virus vector, ALVAC is a plaque-cloned derivative of Kanapox which is a licensed canarypox vaccine. ALVAC is a ubiquitous vector with high biosafety that replicates only in avian species, providing an important safety barrier for human use. The canarypox vaccine vector technology has been used to develop several vaccines for mammal animals including humans.

TROVAC

As an attenuated fowlpox, TROVAC was a plaque-cloned isolate derived from the FP-1 vaccine strain of fowlpoxvirus, which is licensed for vaccination of one day old chicks. Just like ALVAC, these viruses replicate only in avian species and therefore do not cause clinical infections in humans.

LC16m8∆

The LC16m8 strain of vaccinia virus is an active ingredient in the Japanese smallpox vaccine. It was derived from the Lister/Elstree strain. LC16m8∆-based vectors induce both antibody- and cell-mediated immune responses against foreign antigens more efficiently than non-replicating VACV vectors. Thus, LC16m8∆ is more suitable for use in humans. The safety and efficacy of LC16m8∆ make it a promising vector for vaccines of human diseases such as HIV.

Features

• Simple and inexpensive to manufacture.
• Stable in the freeze-dried state.
• A single dose can provoke a life-long immunity
• Stimulating both humoral and cell-mediated immune responses

Creative Biolabs specializes in creating novel vaccine technology platforms to promote the prevention and treatment of infectious diseases and cancer. Vaccinia virus vaccine vectors represent a promising potential as a safe effective vaccine platform. We strive with competence and confidence to meet your demand for creating novel vaccines using VACV vectors and to promote vaccine development.

All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.