The human immune system takes apart microbial pathogens and manufactures antibodies to a variety of sites on the microbe, honing its response as the infection progresses. Nearly 40 years ago, scientists became able to create antibody-producing cell lines that did not die, and could produce an infinite amount of antibodies of one type. So, if you can figure out which are the most effective antibodies at fighting an infection, this system allows you to produce as many of them as you want, in cell cultures or other platforms. ZMapp is a mix of 3 different monoclonal antibodies. The owner of ZMapp used tobacco plants to grow the antibodies. This is a clever approach, since tobacco plants grow rapidly. But for reasons not known to me, the manufacturer could not or would not scale up for rapid production.
But maybe ZMapp does not have the optimal choice of antibodies. Maybe more than 1, or more than 3 antibodies, are needed. Maybe certain antibodies must work together, and so specific combinations are needed. This is not clear to scientists.
Furthermore, the best antibodies would be designed with the newest version of the pathogen in mind, based on blood from victims who survived. ZMapp's 3 antibodies came from older Ebola Zaire strains. For reasons unknown to me, the US military appears to have a lock on the newest strains, and is not sharing them.
Finally, use of monoclonal antibodies, or of plasma products (which were used for most of the US Ebola survivors), has its own set of sometimes very serious side effects. This paper discusses adverse effects of monoclonals. Plasma products are best known for transmitting viruses, but can have other problems as well. Over thirty years ago, as an intern, I received Hepatitis B immune globulin (one such product) and developed hepatosplenomegaly, lymphadenopathy and six months of fatigue.
A group of scientists including three Nobel laureates in medicine has proposed that U.S. health officials chart a new path to developing Ebola drugs and vaccines by harnessing antibodies produced by survivors of the deadly outbreak.
The proposal builds on the use of "convalescent serum," or survivors' blood, which has been given to at least four U.S. Ebola patients who then recovered from the virus. It is based on an approach called passive immunization, which has been used since the 19th century to treat diseases such as diphtheria but has been largely surpassed by vaccination...