SWATT team helps double flu vaccine output

A Canadian firm that has developed a technology to double the amount of flu virus obtained during traditional egg-based vaccine production is launching a dedicated team to help manufacturers implement the platform and ramp up their production capabilities.

Microbix Biosystems is establishing its SWATT team - Special Workgroup for Applied Technology Transfer - to help interested vaccine manufacturers effectively double their virus yield through the use of Microbix' proprietary technology, Virusmax.

Last year an independent lab confirmed that the novel system considerably upped the yield of human flu virus obtained from eggs, with a two-fold increase over traditional methods. In addition to this, the company claims that the relatively simple procedure can be easily implemented in standard vaccine manufacturing processes and involves limited capital costs to install.

The Virusmax system is based on the fact that during standard egg-based vaccine manufacture, a significant volume of virus becomes attached to debris in the allantoic fluid of the chick embryo (the standard raw material for flu vaccine) and is then routinely discarded.

Commercial flu vaccine production usually involves a step by which the used allantioc fluid is clarified by centrifugation, resulting in a clarified liquid that goes on to further processing, and a debris-containing faction that is disposed of.

By developing a method by which the virus can be recovered from the debris, Microbix has given manufacturers access to a source of virus that was previously wasted, allowing them to potentially double their vaccine output.

The recovery process by which the virus can be dissociated from the debris is achieved by subjecting the debris-virus aggregate to conditions of increased ionic strength (through salt treatment) at defined pH levels.

Although the level of increased virus yield that can be achieved varies depending on the specific strain being used, the company reported enhanced yield in all type A and type B influenza strains tested.

The NaCl used in the process is inexpensive and non-toxic, meaning that integration into a vaccine manufacturing process and regulatory approval should be relatively straightforward.

The SWATT initiative being launched by Microbix will be a standard part of the integration of the system into manufacturing facilities implementing the technology, with the team headed up by experienced company representatives who have been involved in the development of the Virusmax system.

Although the platform has yet to be installed in a commercial vaccine production facility, Microbix CEO Bill Gastle hopes the first plants will be kitted out with the Virusmax technology within the year, with a number of manufacturers already having shown interest in the system.

According to Microbix, the global influenza vaccine market is expected to exceed $4bn by 2012, and the company has 'conservatively' estimated that the world market for its Virusmax product could be in excess of $100m a year.

The short-fall in global vaccine manufacturing capacity is well-known, and a constant source of angst for bodies such as the World Health Organization, which has been pushing research into measures to combat this deficit in production to defend against the threat of a pandemic outbreak.

Much work has been carried out into the possibility of cell-based vaccine manufacture, seen by many as the future of vaccine production thanks to the advantages it appears to offer in terms of vastly reduced production times.

However, Gastle does not see the increased interest in cell-based manufacture as any kind of real threat to the potential of Microbix' Virusmax technology.

"There's been a lot of promotion by government bodies of cell-based manufacture…but it will never replace egg-based vaccine production, particularly because of the costs involved," he told US-PharmaTechnologist.com.

Despite the substantial investment in developing tissue culture manufacturing processes, Microbix points out that the higher costs of this method will lead to a significant price increase (five to ten times, according to the company) to buyers.

Conversely, the Virusmax technology promises to reduce production costs by doubling virus yields with only limited expenditure.

"Embryonated chicken eggs will remain the production substrate for influenza vaccine for the foreseeable future," a recent paper on the company's technology in the international journal Vaccine stated.

"The yields realized by this approach still far outstrip those of cell culture-based strategies. By including the high ionic strength extraction strategy in these production processes, eggs can continue to be the mainstay of influenza vaccine production."