VanCott T, Earl P, Steinmeyer L, Frampton L, Cox J, Ratto-Kim S, Jagodzinski L, Kakareka C, Olson R, Excler JL, Eckels K, Moss B, Birx D.
AIDS Vaccine 2001. 2001 Sep 5-8; abstract no. 231.
US Military HIV Program, Rockville, MD, USA
BACKGROUND: MVA alone or in combination with DNA vaccine priming has afforded protection from disease after SHIV challenge in rhesus macaques. We have constructed an rMVA expressing env, gag, and pol genes from a subtype E/A HIV-1 isolate (rMVA-E/A) for phase I vaccine trials in the US and Southeast Asia.METHODS: Subtype E/A rMVA consisting of env, gag, and pol (protease and RT only) was constructed and in vitro expression of gene products was demonstrated. GMP vaccine production and vialing was performed. Vaccine immunogenicity, stability, and QA/QC testing of vialed material were assessed.RESULTS: rMVA-E/A was formulated in PBS, pH 7.4, with 7.5% lactose with a final vaccine yield of 1 ( 10[11] pfu providing sufficient vaccine doses for a phase I clinical vaccine trial. Vaccine titers were stable after 9 months storage at (80(C. Immunogenicity studies of GMP vialed material in BALB/c mice demonstrated env and gag-specific serum IgG. Gag-peptide-specific splenic CD8 T-cell IFN-g responses were detected by ELISPOT and intracellular cytokine staining. All general and product-specific QA/QC safety, sterility, and potency testing of vialed material passed except for the detection of bovine viral diarrhea virus (BVDV, contaminant of FBS) in the Master Seed thus delaying this vaccine lot from transitioning to clinical phase I testing. An in-house BVDV-specific nested RNA PCR assay was developed and used to identify a BVDV RNA-negative commercial lot of FBS. Using this FBS, we have developed a purification strategy combining an ether extraction step with passage in primary CEF cells and sucrose cushioning that eliminated detectable BVDV RNA in the rMVA-E/A vaccine.CONCLUSIONS: GMP rMVA vaccine expressing subtype E/A HIV antigens was manufactured and vialed of sufficient titer, stability and immunogenicity for clinical evaluation. Development of a purification strategy to remove BVDV and further purify rMVA has enabled us to resume GMP production of rMVA-E/A for advancement to a phase I clinical evaluation of safety and immunogenicity.
Publication Types:
Keywords:
- Animals
- Asia, Southeastern
- CD8-Positive T-Lymphocytes
- Cattle
- Genes, env
- Genes, gag
- Genes, pol
- HIV Antigens
- HIV Envelope Protein gp120
- HIV-1
- In Vitro
- Macaca mulatta
- Mice
- Vaccines, DNA
- genetics
- immunology
- reverse transcriptase, Human immunodeficiency virus 1
Other ID:
UI: 102249307
From Meeting Abstracts