Ebola convalescent serum: effective therapy?

[Chicagogal]

The assistant nurse infected with Ebola admitted to La Paz Hospital Carlos III of Madrid being treated with serum from sister Paciencia Melgar, who had the disease in August, and did not survive...

Does that seem like a useful course to others? This summary of Ebola pathogenesis indicates there is a marked difference in the immune response between those who live and those who don't:

Survivors exhibited more significant IgM responses, clearance of viral antigen, and sustained T-cell cytokine responses, as indicated by high levels of T-cell-related mRNA in the peripheral blood. In contrast, antibodies specific for the virus were nearly undetectable in fatal cases, and while gamma interferon (IFN-γ) was detected early after infection, T-cell cytokine RNA levels were more indicative of a failure to develop adaptive immunity in the days preceding death.

I've read that IgG antibodies are the only ones that are protective across multiple strains of Ebola. Perhaps it would make more sense at this point to start a blood draw program from those in endemic areas, since as high as ~20% of populations in these areas demonstrate antibodies to Ebola. There just won't be enough survivor serum to go around.

 

[Gert van der Hoek]

Re: Ebola Convalescent Serum: effective therapy?

Re: Ebola Convalescent Serum: effective therapy?

Wednesday, September 17, 2014

Ebola Convalescent Serum: It's No Magic Bullet

There have been many questions since Dr. C.J. Peters was quoted here (9/8/14) saying that convalescent serum from Ebola survivors was unlikely to help treat patients. In this post I go into detail about the data we have that supports this statement. In a future post I will discuss the why of it.

OK. Much of what's been said in the media and by scientists gives the illusion that the effectiveness of Ebola convalescent blood as a treatment for Ebola virus disease is an established and recognized fact. WHO's endorsement and the New York Times article on it has, I think, given people some false hope.

Don't get me wrong. West Africa is in a tough spot and I understand why it's being tried. Why not? What else do we have to offer these people? But that doesn't mean it will work. And while I strongly encourage doing everything we can think of to help people, in a situation with limited resources we should focus on those options with the most data to support them and avoid things that might make the situation worse.

Since the WHO's announcement, survivor blood has become a hot commodity and now there's a black market for it. How many will suffer a second time because others will surely go to great lengths to get their blood? Blood that will most likely turn out to be unhelpful. But unfortunately, most looking at this situation (like me before I researched it) only know that convalescent serum can work really well for some viruses so they assume it's worth trying.

Unfortunately all viruses are not created equal and if those considering this treatment actually looked at the data for Ebola they would see that it tells us this new treatment strategy will almost certainly fail. So let's take a look at this data.

(.........)

"However, the results of the present study, which used immune primate blood, joins the preponderance of published study results suggesting that immunotherapy will not be a shortcut to the solution. Given these discouraging results and the risks of transmitting infection, whole blood transfusions, even under desperate epidemic conditions, seem unwarranted."

As desperate as we are for a way to help these patients, we simply have no solid platform from which to proclaim Ebola survivor blood as effective therapy. With a black market for blood, my fear is that already stigmatized survivors will be further targeted. We have a responsibility to make sure people are informed.

Read more: Pathogen Perspectives