Study findings on smallpox vaccines are outlined in reports from Food & Drug Administration
2007 NOV 19 -- "The licensed smallpox vaccine Dryvax is used as the standard in comparative immunogenicity and protection studies of new smallpox vaccine candidates. Although the correlates of protection against smallpox are unknown, recent studies have shown that a Immoral response against the intracellular mature virion and extracellular enveloped virion (EV) forms of vaccinia virus is crucial for protection," scientists in the United States report. "Using a recombinant Semliki Forest virus (rSFV) vector system, we expressed a set of full-length EV proteins for the development of EV antigen-specific enzyme-linked immunosorbent assays (ELISAs) and the production of monospecific antisera. The EV-specific ELISAs were used to evaluate the EV Immoral response elicited by Dryvax and the nonreplicating modified vaccinia virus Ankara (WA) in mouse vaccination experiments comparing doses and routes of vaccination. Quantitatively similar titers of antibodies against EV antigens A33R, A56R, and B5R were measured in mice vaccinated with Dryvax and WA when MVA was administered at a dose of 108 plaque-forming units. Further, a substantial increase in the EV-specific antibody response was induced in mice inoculated with WA by using a prime-boost schedule. Finally, we investigated the abilities of the EV-expressing rSFV vectors to elicit the production of polyclonal monospecific antisera against the corresponding EV proteins in mice. The monospecific serum antibody levels against A33R, A5611, and 13511 were measurably higher than the antibody levels induced by Dryvax," wrote A.D. Garcia and colleagues, Food & Drug Administration. The researchers concluded: "The resulting polyclonal antisera were used in Western blot analysis and immunofluorescence assays, indicating that rSFV particles are useful vectors for generating monospecific antisera." Garcia and colleagues published their study in Clinical and Vaccine Immunology (Characterization and use of mammalian-expressed vaccinia virus extracellular membrane proteins for quantification of the humoral immune response to smallpox vaccines. Clinical and Vaccine Immunology, 2007;14(8):1032-1044). For more information, contact A.D. Garcia, Food & Drug Administration, Center Biology & Evaluation & Research, Division Viral Prod, 1401 Rockville Pike, HRM-457, Rockville, MD 20892, USA. Publisher contact information for the journal Clinical and Vaccine Immunology is: American Society Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA. Keywords: United States, Rockville, Immunization, Smallpox Vaccines, Vaccination, Food & Drug Administration. This article was prepared by Pharma Business Week editors from staff and other reports. Copyright 2007, Pharma Business Week via NewsRx.com.
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