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.
Comments
If one family member survives the H5N1 virus, doesn't it take an extended period (several weeks) for antibodies to become measurable? It would seem that the virus would blow through a family, assuming they are infecting each other, long before a transfusion from a surviving family member would help. Perhaps the help is for those who are untouched by the first wave, but who succumb during the second wave.....
Posted by: limestone | August 31, 2006 10:39 AM
So Revere speculate for me. I had the 57, the 68, was vaccinated every year of my life for flu and for Swine (yeah and it hurt like hell and I got sick but only mildly), and every year up until 98 for flu. Quit because the shots made me sick and I never got the flu ever. I donate now and I dont have that squirrely virus that like 80% of the people have in their blood so I can give it to babies. I am 52 now. Would my blood be possibly already loaded with antibodies even though its A strain. Swine was A strain too I think, as was 57, 68 etc. I never get sick.
Posted by: M. Randolph Kruger | August 31, 2006 10:26 PM
Randy: You want me to speculate with your life? You are even crazier than I thought.
If I had to guess the most probable outcome I'd say you were somewhat protected against N1 viruses and maybe even H5N1. But most probable might not mean much if the next most probable is almost as likely.
This advice is worth twice as much as what I'm charging. I'm, also charging twice what it's worth.
You do the math.
Posted by: revere | August 31, 2006 10:45 PM
One of the problems with this approach is that it takes at least 2 weeks for antibodies to show up. In some of these cases the virus might not have been cleared entirely, so one runs the risk of infecting someone. The risk is probably fairly small but not trivial. We don't know if H5N1 has the potential for cryptic infection.
Posted by: Marissa | September 1, 2006 8:16 AM
I wonder if simply injecting someone with H5N1 would produce a survivable response. This is your field I think Revere. If you get H5 in your lungs, they respond pretty much like someone rammed a flamethrower down them. On the other hand if you are simply blood infected would it transfer to your lungs and start reproducing and give you cytokine storm? I dont know the mechanism of a blood infection if its in your body first rather than your lungs. We already know what happens to the lungs.
Posted by: M. Randolph Kruger | September 1, 2006 10:26 PM