Replication-competent viral vectors

Published on June 11, 2015   45 min

Other Talks in the Series: Vaccines

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My name is Farshad Guirakhoo, and I am Chief Technology Officer at Vaxess Technologies located in Cambridge, Massachusetts. I will be talking about replication competent viral vectors.
I will be talking about virus classification, infectious diseases in humans caused by viruses, and vaccine approaches to combat such diseases. Next, I will focus on vaccines based on viral vectors, general barriers and challenges, then describe specific characteristics and challenges for both replication diffusion and replication-competent vectors. The talk will be then narrowed specifically on replication-competent vectors, starting with describing the rationale for this selections, and going onto a few examples of replication-competent vectors which are either in clinical development or already marketed. These include VSV, or vesicular stomach virus, or yellow fever-based replication-competent vectors. A summary slide will conclude this presentation.
One may wonder how many viruses are actually on the planet Earth. The answer is, nobody knows at this time. But one estimate puts the number of viruses in mammals at more than 320 thousand. If one adds invertebrates, plants, mushrooms, and Brown Algae species, for example, the number could go to several hundred millions. Viruses are classified by International Committee of Taxonomy of Viruses, or ICTV, into seven orders, 103 families, 22 sub-families 455 general, and 2,827 species with many thousands of types unclassified. This traditional classification is generally used with the new classification proposed by David Baltimore, which is based on the mechanism of messenger RNA production. As you know, viruses must generate messenger RNA to produce proteins and replicate themselves. But different mechanisms are used to achieve this in each virus family. Viral genome may be double stranded or single stranded, RNA or DNA, and may or may not use reverse transcriptase, or RT. In addition, single stranded RNA viruses may be either positive-sense or negative, or anti-sense. This classification places viruses into seven groups.