An article in the current issue of Annals of Internal Medicine again raises the issue of passive immunization to treat H5N1 using plasma from recovered cases (Eurealert). The idea is that antibodies against H5N1 in the convalescent blood of a recovered case would be therapeutically effective. This is an old idea and was tried in the 1918 flu pandemic. The current paper is said to be confirmed by a handful of uncontrolled studies published ninety years ago during that catastrophe. The idea certainly has biological plausibility.
It also has the feeling of an act of desperation. The logistics of bleeding recovered cases and then figuring out who would get the precious antiserum suggests that even if this worked, it would benefit a favored few relative to the need in a true pandemic. Saving even a few by an effective treatment is not to be discouraged, provided it doesn’t come at an even greater opportunity cost in terms of the resources needed to carry it out. There is also the not so minor issue of the scientific work that needs to be done to determine whether it really does work and if so, what effective dosage might be.
This is one of those ideas that sounds good on paper until one thinks of bodies stacked up like cordwood outside of emergency rooms. As a strategy, except in exceptional circumstances, this seems like a pretty weak reed to lean on. The time to investigate it and try it is now, when cases are few and this method might be used in resource scarce Indonesia, Thailand or China. In these instances, if effective, it might save someone’s little girl or big brother. It should be tried.
But if this virus becomes easily transmissible, this isn’t a treatment that’s going to make much difference.