Summary of Invention The invention relates to the use of the herpes simplex virus (HSV) in a vaccine capable of inducing a CD8+ immune response in an animal and in a method of screening heterologous candidate antigens for use in vaccines. The use of vaccination to combat disease is well known and has, in some cases, such as smallpox, been so successful that it has lead to the eradication of the disease to which it is targeted. Viruses are often used in vaccines, either in an attenuated form or in a fully functional form. Viruses are often referred to as vectors and are frequently used to deliver antigens. A large number of viral vectors are known for use in vaccines. These may include poxvirus-based vectors, alphavirus self- replicating vectors, adenovirus, and lentivirus, for instance. Many of these viral vectors are known for their capacity to induce in vivo strong Th1 and CTL responses, as well as antibody titres against various antigens, such as HIV-1 gene products. HSV vectors for use in prophylaxis against, for instance, viral infections, show several advantages. HSV vectors have been shown to elicit strong and durable immune responses by various routes of inoculation; the viral DNA persists inside the host's cell nucleus as an episomal element, thus eliminating safety concerns arising from possible random integration of the viral genome into the host's DNA. However, despite recent advances in vaccine technology, bacteria, viruses and cancers still result in a high proportion of fatalities. In particular, viruses such as HIV have resulted in the deaths of millions of people worldwide whilst tumours leading to cancers are one of the principal causes of death, particularly in the western world. Accordingly, there remains a need in the art for new vaccines, preferably that may be used with a variety of antigens. We have, surprisingly, found that HSV is capable of inducing a strong immune response when encoding a heterologous antigen. Thus, the present invention provides a vaccine capable of inducing a CD8+ immune response in an animal, the vaccine comprising replication- deficient HSV, the HSV comprising polynucleotides encoding a heterologous antigen, preferably, the polynucleotides are DNA. Solution to which problem (s) HSV vectors can elicit strong and durable immune responses by various routes of inoculation; the viral DNA persists inside the host's cell nucleus as an episomal element, thus eliminating safety concerns arising from possible random integration of the viral genome into the host's DNA. Key applications As a viral vectors for use in vaccines. Stage of Development Pre-clinical stage, with in vivo animal modeling studies.

Priority Filing in UK; PCT stage;

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