Vaccine Briefs

G8 endorses plan to accelerate AIDS vaccine development

US President Bush hosted the 2004 Group of Eight (G8) summit of developed nations at Sea Island, Georgia on 8-10 June. The summit endorsed the establishment of a global AIDS Vaccine Enterprise to accelerate efforts to develop an AIDS vaccine that seeks to further encourage scientists from around the world to create vaccine development centers, with the headquarters in the US. Other goals are to support the standardization of laboratory test systems to facilitate comparison of trials from different countries and to build an integrated clinical trials system. The plan also will seek to eliminate red tape so that regulatory agencies from different countries can more easily recognize clinical trials and data. The Enterprise will also seek to stimulate dedicated vaccine manufacturing capacity.

An international group of scientists published a "Policy Forum" in Science magazine last year (300:2036, 2003) calling for a virtual consortium to accelerate AIDS vaccine development by enhancing coordination, information sharing, and collaboration globally. The G8 has now endorsed this concept in a statement calling on the Enterprise to “establish a strategic plan that would prioritize the scientific challenges to be addressed, coordinate research and product development efforts, and encourage greater use of information sharing networks and technologies. This plan should serve as a blueprint for helping to align better existing resources and to channel more efficiently to the needs at hand new resources as they become available.” For more details, visit the G8 Web site at http://www.g8.gc.ca/.

GenVec and NIH move AIDS vaccine candidate into clinical trials

GenVec, Inc., a biotech company based in Gaithersburg, Maryland, announced last month that the Vaccine Research Center of the National Institute of Allergy and Infectious Diseases (NIAID) has initiated a Phase I clinical study to test an AIDS vaccine candidate that uses GenVec's proprietary modified adenovirus particles as vectors, consisting of a second generation type 5 adenovirus with E1, E3 and E4 deletions. The vector is currently being used in other unrelated human trials.

The recombinant products used in this trial are composed of four adenoviral vectors (in a 3:1:1:1 ratio) that encode an HIV-1 Gag/Pol fusion polyprotein from clade B and HIV-1 Env glycoproteins from clades A, B, and C, respectively. The vaccine will be given to 36 healthy volunteers, most from the Washington DC area to determine the “safety, tolerability, immune response of a multiclade HIV adenoviral vector vaccine in uninfected adults.” The study will be sponsored, managed and funded by NIAID.

The US$30 million NIH contract covers production of vaccines for both AIDS and SARS, or severe acute respiratory syndrome. This Phase I, dose-escalating, double-blind, placebo-controlled study is designed to assess safety and immunogenicity of a vaccine candidate targeting clades A, B, and C, and intended to induce both humoral and cell-mediated immunity. NIAID Director Anthony Fauci told the Wall Street Journal that, while the vaccine candidate did not protect monkeys from infection, they did show a less severe course of disease. For more details, visit the IAVI Database of AIDS Vaccines in Human Trials at /trialsdb/.

US Army begins small Phase I trial

AVANT Immunotherapeutics, Inc. announced in May that the Walter Reed Army Institute of Research (WRAIR) has initiated a Phase I clinical trial to assess the safety and immunogenicity of an AIDS vaccine based on AVANT's Therapore technology. Therapore utilizes bacterial toxin proteins to deliver target antigens into human cells to induce cell-mediated immune responses. The WRAIR AIDS vaccine, designated LFn-p24, is comprised of aBacillus anthracis-derived polypeptide called lethal factor from which the toxin domain has been removed (LFn) fused to the HIV Gag p24 protein. The vaccine is aimed at inducing strong and persistent HIV Gag specific CD8+ T-cell responses.

The placebo-controlled trial is evaluating the vaccine at three escalating dose levels in 18 healthy adult volunteers. Volunteers in each of the three dose groups in the study will receive three intramuscular vaccine immunizations or placebo injections at weeks 0, 4 and 16 and will be followed for at least 36 weeks following their final dose. The trial, under the direction of principal investigator CDR Shirley Lee-Lecher, is being conducted at the WRAIR Vaccine Clinical Research Center in Rockville, Maryland in conjunction with the Division of AIDS, National Institute of Allergy and Infectious Diseases (NIAID). WRAIR and NIAID are working together through an established interagency agreement.

*Roberto Fernandez-Larsson, Ph.D., is the IAVI Report Web editor.