Plant-made vaccines and reagents for the One Health initiative

Rybicki, Edward Peter

Perhaps the crowning achievement of molecular farming in recent years is one specifically related to the recent West African Zaire ebolavirus outbreak: this was the production and eventual accelerated clinical trial of the humanised mAb cocktail known as ZMapp TM by Mapp Biopharmaceutical, made by transient expression in N benthamiana. 30 This has been thoroughly described elsewhere, 9, 31 and suffice it to say here that this one product has done more in terms of raising the profile of plant-produced pharmaceutical products in general, and therapeutics in particular, than any other. In the clinical trial in West Africa, 36 trial participants were randomly assigned to each of the 2 study arms: mortality in ZMapp TM -treated participants was lower (8 of 36; 22 percent mortality) than in participants receiving standard-of-care alone (13 of 35; 37 percent mortality). While this was not statistically significant because the participant numbers were low, ZMapp TM -treated participants eliminated virus from the bloodstream faster, had more rapid resolution of symptoms and were discharged from care earlier, than untreated participants. Given this apparent success, the US Government has funded Kentucky BioProcessing to stockpile the MAbs, and Mapp is going ahead to license ZMapp TM as a therapeutic for use in subsequent Ebola disease outbreaks. 30 It should be noted that the MAbs should also be highly useful in the diagnostic arena.