Almost Only Counts in Horseshoe(crabs) and COVID-19

BALTIMORE一The COVID-19 vaccine is in mass distribution and pharmaceutical companies are relying on horseshoe crabs to check new batches for toxins. 

The bright blue blood of the horseshoe crab has a special quality that allows the blood to coagulate around bacteria introduced to their system and has been used by medical companies for decades to check everything from knee replacements to the recent COVID-19 vaccine. 

Horseshoe crabs are native to the east coasts of the United States and Asia and have traditionally been used as eel bait. Roughly 50,000 crabs die from blood harvesting by medical companies a year according to a June 2020 article from the Smithsonian Magazine. 

 “About three tablespoons extracted from a live, wild horseshoe crab is refined and used to detect toxins in everyday medical products: saline drips, flu shots, heart stents… and now Coronavirus,” said a Dec. 31 article from the Baltimore Sun. 

The unique trait was discovered in 1956 by Dr. Frederik Bang, while he was studying the circulation of vertebrae to better understand physiology. 

Bang accidentally stumbled upon the phenomenon after a natural bacterium was introduced to a sample of the horseshoe crabs’ blood said John Hopkins Bloomberg School of Public Health.

 Almost a decade later in 1963, Dr. Jack Levin spent a summer with Bang in Cape Cod, Massachusetts, where he took the experiment a little bit further. 

Levin and his colleagues discovered that they could take parts of the horseshoe blood and use it to test for endotoxins. The Limulus amebocyte lysate (LAL) test was approved by the FDA in 1977.