Hi Douglas, I am glad you asked this question because I happen to work in this field at present. My current mentor and the principal investigator of my clinical research endeavors, Dr. Howard L. Kaufman, MD, is a pioneer of poxvirus based gene expression vectors used as tumor vaccines, and he is indeed one of the leading researchers of tumor immunology, including the use of oncolytic viral vaccines. I have included a short list of his publications pertaining to gene therapies for cancer treatment below. I am personally working on follow-up data pertaining to the first study listed below, which is really quite a thrilling one that gave me a great idea of where viral vector gene therapies are headed. If you would like a review of this type of genetic therapy, see the very last paper.

1. OPTIM trial: a Phase III trial of an oncolytic herpes virus encoding GM-CSF for unresectable stage III or IV melanoma. Kaufman HL, Bines SD. Future Oncol. 2010 Jun;6(6):941-9

2. Gene therapy for antitumor vaccination. Kim-Schulze S, Kaufman HL. Methods Mol Biol. 2009;542:515-27.

3. Phase II trial of Modified Vaccinia Ankara (MVA) virus expressing 5T4 and high dose Interleukin-2 (IL-2) in patients with metastatic renal cell carcinoma. Kaufman HL, Taback B, Sherman W, Kim DW, Shingler WH, Moroziewicz D, DeRaffele G, Mitcham J, Carroll MW, Harrop R, Naylor S, Kim-Schulze S. J Transl Med. 2009 Jan 7;7:2

4. Intrarectal vaccination with recombinant vaccinia virus expressing carcinoembronic antigen induces mucosal and systemic immunity and prevents progression of colorectal cancer. Kim-Schulze S, Kim HS, Wainstein A, Kim DW, Yang WC, Moroziewicz D, Mong PY, Bereta M, Taback B, Wang Q, Kaufman HL. J Immunol. 2008 Dec 1;181(11):8112-9

5. Combination chemotherapy and ALVAC-CEA/B7.1 vaccine in patients with metastatic colorectal cancer. Kaufman HL, Lenz HJ, Marshall J, Singh D, Garett C, Cripps C, Moore M, von Mehren M, Dalfen R, Heim WJ, Conry RM, Urba WJ, Benson AB 3rd, Yu M, Caterini J, Kim-Schulze S, Debenedette M, Salha D, Vogel T, Elias I, Berinstein NL. Clin Cancer Res. 2008 Aug 1;14(15):4843-9

6. Poxvirus-based vaccine therapy for patients with advanced pancreatic cancer. Kaufman HL, Kim-Schulze S, Manson K, DeRaffele G, Mitcham J, Seo KS, Kim DW, Marshall J. J Transl Med. 2007 Nov 26;5:60

7. Improving tumor targeting and therapeutic potential of Salmonella VNP20009 by displaying cell surface CEA-specific antibodies. Bereta M, Hayhurst A, Gajda M, Chorobik P, Targosz M, Marcinkiewicz J, Kaufman HL. Vaccine. 2007 May 22;25(21):4183-92. Epub 2007 Mar 22

8. Viral vaccines for cancer immunotherapy. Eisenberger A, Elliott BM, Kaufman HL. Hematol Oncol Clin North Am. 2006 Jun;20(3):661-87. Review

9. 4-1BB ligand enhances tumor-specific immunity of poxvirus vaccines. Kudo-Saito C, Hodge JW, Kwak H, Kim-Schulze S, Schlom J, Kaufman HL. Vaccine. 2006 Jun 5;24(23):4975-86. Epub 2006 Mar 31

10. Manipulating the local tumor microenvironment with poxviruses expressing costimulatory molecules. Kaufman HL. Ann N Y Acad Sci. 2005 Dec;1062:41-50. Review

11. Local delivery of vaccinia virus expressing multiple costimulatory molecules for the treatment of established tumors. Kaufman HL, Cohen S, Cheung K, DeRaffele G, Mitcham J, Moroziewicz D, Schlom J, Hesdorffer. Hum Gene Ther. 2006 Feb;17(2):239-44

12. Development of the PANVAC-VF vaccine for pancreatic cancer. Petrulio CA, Kaufman HL. Expert Rev Vaccines. 2006 Feb;5(1):9-19. Review

13. Pox viral vaccine approaches. Arlen PM, Kaufman HL, DiPaola RS. Semin Oncol. 2005 Dec;32(6):549-55. Review

You can always find more, as well, by reading journals like Human Gene Therapy, or just typing in key words using PubMed MeSH. I hope this helps and good luck!

Be sure to also read some review papers on AAV vectors, as they are currently being used for gene transfer in humans (LCA (blindess), hemophilia, LPL deficiency):

http://www.ncbi.nlm.nih.gov/pubmed/21499295

http://www.ncbi.nlm.nih.gov/pubmed/21781236

You should also consider the field of messenger RNA based therapies.

http://www.mrna-conference.com