So called “farmaceuticals” — genetically engineered animals that express drugs in their milk — has long been predicted as a likely eventual outcome of biotechnology efforts and that possibility took a big step forward with the recent announcement of initial success using mice to produce a malaria vaccine for monkeys. This advances is especially noteworthy since the technique used should scale well to larger animals such as goats, which could have an enormous impact on controlling disease in the developing world.
In this instance, researchers developed mice that secreted an experimental malaria vaccine in their milk. Two separate strains of transgenic mice were created, each of which carried a form of a gene to produce a surface protein of a strain of malaria. The mice were designed so that the gene to produce the proteins could be turned on only by the cells that line the animals’ mammary glands, ensuring that the proteins would be secreted in the milk of the animals.
The vaccine was then purified and injected into monkeys who were then exposed to the malaria parasite. In the extremely small experiment, only one of the five monkeys who received the vaccine contracted malaria, compared to six out of seven monkeys in a control group who did not receive the vaccine.
Doing this with mice is amazing, but here’s where things get very interesting. When researchers designed the mice to express the protein, they used DNA from goats, meaning it should be possible to create goats which also express the protein. In fact Science Daily reports that preliminary, unpublished research suggests the procedure works well in larger animals.
If this result holds, this could revolutionize vaccine research into diseases that largely afflict the developing world. Vaccine research in the developed world is problematic enough. Regulatory and liability issues, combined with expensive manufacturing processes have stunted vaccine research into diseases that still afflict people living in the developed world. When it comes to research on a vaccine for a disease like malaria, those concerns are even larger given the economic situation of much of the developing world (and hence the likelihood that much of the developing world would be unable to afford such a vaccine even if it were available).
Being able to have such medications produced by a herd of goats, however, would drastically lower the costs of such vaccines. Considering the World Health Organization estimates that as many as 1 million people die annually from malaria-related complications, this technology could have an enormous public health impact.
Scientists Milk Animals for Malaria Vaccine. Science Daily, December 18, 2001.