Manufacturing ignored in HIV vaccine drive
derailed because investigators have not considered manufacturing
processes in the design of their candidates.
The International AIDS Vaccine Initiative issued a report earlier this week that found that for many of the 30 or so vaccine candidates in trials, the process for manufacturing them is slow, expensive and in a few cases not feasible on a large scale. And big pharma needs to get involved to bring its industrial expertise to bear on the problem.
One of the major implications of this finding is that developing nations - which are bearing the brunt of the HIV epidemic and stand to benefit the most from an effective vaccine - could find it impossible to gain access to a successful candidate even if it gets through the testing process.
"Little is being done to engineer better manufacturing processes," said the report, which was presented at the ongoing International AIDS Conference in Bangkok, Thailand, by the IAVI, a non-profit organisation funded by governments and other organisations.
The IAVI also has concerns about the narrowness of research into HIV vaccines - with almost all candidates in trials focusing on the same objective of stimulating cell-based immunity - but sees process engineering as a major oversight that has already killed a number of projects before they reached the clinic.
Process development and scale up have been 'under-emphasized', according to the report. This is due in large part to the fact that the global effort consists mostly of academic centres and small biotechnology firms supported by public sector resources, which do not have the industrial experience to address these process development issues.
In general, this sort of oversight causes product inconsistency that can compromise trial results, delays between approval and launch and product failure.
Some of the main factors that are not being considered include cell substrate selection characterisation for production of the vaccine, analytical assay development for release of the vaccine, and process work to go from lab scale via pilot scale to eventual large-scale manufacturing.
The report notes that despite more than a decade of work on vaccines based on modified Vaccinia antigen-based vaccine vectors, only a single MVA-vectored preventive AIDS vaccine has entered clinical trials, due in part to process development issues.
"Mechanisms need to be established to bring the process development expertise from pharmaceutical companies and large-scale vaccine manufacturers to the product development efforts now being conducted by academic, government and biotechnology laboratories," the report concludes.
Copies of the report - entitled Scientific Blueprint 2004: Accelerating global efforts in AIDS vaccine research and development - are available on the IAVI's website.
