The Mail & Guardian‘s cover story last week (”Furore over ‘mutant’ Aids vaccine”) is a source of dismay.
Put simply, without all the negative spin, the story is this: the South African Centre for Scientific and Industrial Research (CSIR), and various partners who are world leaders in their research fields, will attempt to produce various vaccines and monoclonal antibodies in plants.
These plants will be grown, and the products possibly tested, in South Africa and elsewhere. This is in line with developments in numerous centres elsewhere in the world, accorded high priority for funding by large and reputable bodies such as the Bill and Melinda Gates Foundation and the European Union. Plants are simply being used as alternative production vehicles for products which are known to be effective when made in other systems — because of the potentially far lower production costs in plants.
The word ”mutant” is inappropriate: the vaccines and antibodies are no more mutant than if produced in bacteria, yeast or animal cells, the more conventional means of production.
It is very strange that the people who are objecting to plants being used to produce vaccine proteins would rather see bacteria used. They are obviously unaware of the problems in doing this, such as the fact that bacteria do not make proteins like plants, yeast or mammalian cells. There are also well-founded dangers in using human and mammalian cells to produce live or even dead vaccines, including possible contamination by nasty viruses.
Plants not only make proteins essentially as we do, but cannot be infected by anything harmful that would be co-purified in a vaccine. Thus, any concern about using plants rather than another system to produce the identical products is misplaced.
The M&G‘s emphasis on concerns of environmental groups is also misplaced. As Dr Blessed Okole of the CSIR says, the production of any possible candidate transgenic plant will be under strict containment; moreover, it will almost certainly be on a minute scale compared to ”conventional” transgenic crops because of the low-volume, high-value nature of the product!
The CSIR is proposing to produce an amount of crop small enough to be done under strict containment, and even in quarantined glasshouses. This should be more than enough to satisfy the concerns of the Safe Food Coalition and others.
As for such a project being ”environmental racism”, this is ridiculous. The activists are making out that the technology is being dumped on South Africa, whereas what it amounts to is the transfer of some very desirable technology to an entirely appropriate venue.
The products will not be ”foods” — any drugs or vaccines made from the transgenic plants will be processed products, subject to purification and strict quality and dose control, even if intended for oral use.
It is also easy to use plant varieties which can very easily be kept apart from commercially-produced versions. Non-commercial tobacco cultivars, for example, or maize with pigmented seeds could be used, which could not possibly be mistaken for any other variety.
In addition, neither maize nor tobacco has natural plant relatives in Africa, so the spectre of ”genetic contamination” is a non-starter. Tobacco is also not a food crop, and alternative uses for it should be welcomed rather than rubbished!
It is also strange that there should be so much fuss about this project, when my research group is also involved in locally funded projects which use plants to produce candidate human vaccines well publicised in the print and audiovisual media in South Africa and elsewhere. Is this another case of misplaced xenophobia, where local equals good and foreign equals bad?
Andrew Taynton of the Safe Food Coalition is disingenuous to dismiss the claims that lower production costs are the aim of the transgenic plant investigations, and to claim that patenting the medicines will perpetuate high costs.
The potential cost saving of producing pharmaceutically active proteins in plants is well documented. Not to patent a biotechnology is tantamount to throwing it away in terms of its potential for commercial use!
For example, Large Scale Biology Corporation in the United States has used patented technology to produce in plants what will almost certainly be the cheapest personalised non-Hodgkin’s lymphoma vaccines available. This could allow the treatment of individuals with vaccines tailored to their own specific disease, at costs compatible with standard US medical insurance rates.
Taynton’s inference that South Africa has ”very lax biotechnology legislation” is also unfounded — our legislation is more permissive of the introduction of genetically modified plants because it is enlightened and forward-looking, not because it is lax.
If anyone is in doubt about the potential of this approach, they should read the account of the first conference on the subject — Plant-Derived Vaccines and Antibodies: Potential and Limitations — held in Annecy, in the French Alps, in March this year. The report can be seen at www.mcb.uct.ac.za/ed/Annecy.htm.
The encounter was marked by an incredible optimism among the participants, who came from all over the world, about the prospects for revolutionising the manufacture of vaccines and therapeutics by the use of transgenic plants for their production.
One of the most uplifting presentations was given, not by a representative of big pharma, but by Dr Carlos Borroto of the Centre for Genetic Engineering and Biotechnology in Havana, Cuba. They are planning to use transgenic tobacco to produce monoclonal antibodies to assist in the manufacture of their yeast-produced subunit vaccine against hepatitis B virus. This is marketed to more than 50 countries worldwide, including South Africa
The Cubans have to sacrifice many thousands of mice a year to obtain the same product. I don’t know about the Safe Food Coalition, but in my book the use of tobacco to replace mice to manufacture a pharmaceutical product represents an ethical step forward.
The stated intention of a number of groups — including very prominent vaccine pioneers and bodies like the Cuban and Indian governments — to go ahead with the development of ”orphan” vaccines and therapeutics, such as vaccines for diarrhoeal pathogens and monoclonal antibodies specific to the rabies virus, should completely negate most nay-sayers’ concerns.
Professor Ed Rybicki is a member of the Plant-Based Vaccines Group in the department of molecular and cell biology and Institute of Infectious Disease and Molecular Medicine at the University of Cape Town