Adjuvants and Formulation
of HIV-1 Env Vaccines
A meeting to review criteria for adjuvant selection and assays to monitor protein stability
HIV Env protein-based vaccine candidates aim to induce robust, durable, and protective Env-specific antibody responses. However, recombinant antigens are inherently less immunogenic than attenuated or whole-killed vaccines. Therefore, adjuvants have become increasingly more common in recombinant subunit vaccines. Adjuvants not only quantitatively enhance immunogenicity, but also may elicit qualitatively different responses, for example, by differentially modulating the balance between Th1 and Th2 responses or targeting the immune response to mucosal sites.
The National Institute of Allergies and Infectious Diseases (NIAID), together with the Global HIV Vaccine Enterprise (the Enterprise) and the Bill & Melinda Gates Foundation, are organizing a workshop to share the latest knowledge on advances in adjuvant-employing Env protein vaccines. The meeting will contribute to collaborative efforts to facilitate cross-study data comparisons, will inform participants on the latest developments and important considerations in the area of adjuvants, and will identify strategic issues where the Enterprise may play a role in the future.
There is significant data on the effects of adjuvants on the immunogenicity of recombinant proteins, but the usefulness of these data for HIV vaccine research is limited for several reasons. First, most of the data are from alum-based adjuvants and variations of oil-in-water approaches, while data on next-generation adjuvants that target TLRs are limited. Second, it is difficult to extrapolate results obtained with other immunogens, which are generally more stable and less glycosylated than Env protein. Finally, there are large inter-laboratory variations in antigen/adjuvant mixture formulations and in protein stability assays used to characterize these mixtures.
In addition to the scientific complexities, adjuvanted vaccine candidates present further challenges. For example, because regulatory authorities will only review and approve an adjuvant as part of a specific antigen/adjuvant formulation, new combinations typically require a full product development process, which restrains testing and development of new adjuvants for HIV vaccine applications. In addition, antigen/adjuvant formulations necessitate specific expertise that is heavily concentrated in industry, requiring academic researchers to establish relationships with pharmaceutical and biotechnology companies.
Location: Balcony “A” at Natcher Conference Center, NIH campus, Bethesda, MD
Date: 9 July 2014
- Robert Seder, Vaccine Research Center, NIAID
- Nathalie Garçon, GlaxoSmithKline
Topics to be discussed:
- HIV-Env structure and antigenic properties
- Adjuvant selection and evaluation
- Adjuvant formulation and product characterization
- Regulatory and operational hurdles
- Cesar Boggiano, NIAID
- Patricia D’Souza, NIAID
- Magda Moutaftsi, Bill & Melinda Gates Foundation
- Michael Pensiero, NIAID
- Yegor Voronin, Global HIV Vaccine Enterprise
A report will be produced highlighting the major issues discussed during the meeting and summarizing the consensus on key assays needed to characterize HIV-Env/adjuvant formulations.