Monday, June 8, 2020

USP decides to stick with horseshoe crabs for endotoxin testing

For decades, drug companies have depended on a component in the blood of the horseshoe crab to test injectable medicines, including vaccines, for dangerous bacterial contaminants called endotoxins. 
Conservationists and some businesses have pushed for wide acceptance of an alternative test, to protect the horseshoe crabs and birds that feed on their eggs. Earlier this year, these people seemed to be on the brink of success as the nongovernmental group that issues quality standards for such tests moved toward putting the alternative test on the same footing. 
But on Friday, that organization, the U.S. Pharmacopeia, announced that the alternative test known as rFC (recombinant factor C) requires significantly more study. Pharmacopeia representatives said they have 30 years of data on the current test and only two years on the new test so they needed more information. Internationally, the European Pharmacopeia has approved widespread use of the alternative test.
The debate has been widely monitored as demand has grown for testing new vaccines against the coronavirus. Billions of vaccine doses would eventually require endotoxin testing.
This is only one of the likely hundreds of supply chain challenges that COVID-19 vaccines will face, but I regret the horseshoe crabs will be on the short end of the stick... 


  1. FWIW, previous articles I've seen said that the horseshoe crabs are only used for a time, for a finite amount of blood, and then released to live out their lives and reproduce in the wild. I'm not sure if that makes it better or not. It certainly increases the number of different crabs needed to test COVID vaccines, tho.

    1. A lot of them don't survive in the wild after having their blood harvested.


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