Horseshoe Crab Blood Continues to Play a Role in Vaccine Testing, but the Industry Is Evolving

 

Horseshoe Crab Blood Continues to Play a Role in Vaccine Testing, but the Industry Is Evolving

Pharmaceutical companies may soon find it easier to access synthetic alternatives to horseshoe crab blood, a critical component for testing vaccines and medical devices for contamination.

The U.S. Pharmacopeia, responsible for setting national safety standards, recently introduced a proposal on August 22 to streamline the use of these alternatives. This new standard, anticipated to be effective in early 2024, represents one of several changes following an NPR report in June highlighting the lack of oversight in horseshoe crab blood harvesting on the East Coast. This included areas where horseshoe crab eggs serve as essential food sources for rare bird species.

Horseshoe crab blood, known for its blue hue, coagulates when exposed to bacterial toxins. This unique property assists technicians in identifying contaminated products. Decades ago, scientists developed a synthetic substitute for the blood-derived testing ingredient, known as limulus amoebocyte lysate (LAL). These alternatives have since gained widespread acceptance. Most East Coast bleeding companies now offer tests utilizing synthetic alternatives in addition to LAL. In 2020, the European Pharmacopoeia officially recognized the synthetic ingredient as equivalent to the crab-derived one. However, until recently, the U.S. Pharmacopeia had not followed suit, creating additional regulatory hurdles for American drug companies seeking to adopt these alternatives.

Jaap Venema, the chief science officer of the U.S. Pharmacopeia, expressed optimism about this development, saying, "We hope that this will be an encouragement for companies to continue switching to non-animal-derived reagents. We're only expanding opportunities for companies to start using them."

Subsequently, two days later, environmental groups reached a significant settlement in a lawsuit against the South Carolina Department of Natural Resources and Charles River Laboratories, a multinational biomedical company that supplies over half of the pharmaceutical industry's LAL.

The lawsuit alleged that one of the state's practices, allowing unlimited horseshoe crabs to be stored in ponds away from beaches, was harming these creatures and endangering the red knot, a migratory shorebird.

Red knots rely on horseshoe crab eggs for nourishment during their annual migration from South America to the Canadian Arctic. However, they struggle to find these nutrient-rich eggs on beaches when crabs are sequestered during mating season. Over the past four decades, red knot populations have dwindled by 94%, leading to their designation as a threatened species by the federal government.

Charles River and the Department of Natural Resources contested their responsibility for wildlife harm. Nevertheless, the settlement imposes stricter regulations on the company than those typically applied to the horseshoe crab industry in South Carolina. Over the next five years, horseshoe crab harvesting will be prohibited on 30 island beaches, and keeping female crabs in ponds away from the shore will also be banned. The company will be required to hire an independent monitor to ensure compliance with the new rules, and harvesters must report their locations to the state government.

Furthermore, Charles River agreed not to harvest horseshoe crabs from the Cape Romain National Wildlife Refuge near Charleston. A few weeks prior, the U.S. Fish and Wildlife Service had taken a similar step, marking the first federal agency restriction on horseshoe crab harvesting to protect the red knots.

In response to the settlement, a representative from Charles River stated, "Charles River worked collaboratively with wildlife and environmental groups, as well as the S.C. Department of Natural Resources, to align on the best approach for protecting natural resources, while ensuring access to life-saving LAL to protect the medicines and medical devices used by patients worldwide."

Catherine Wannamaker, the lawyer leading the litigation for the Southern Environmental Law Center, hailed the settlement as a significant achievement for conservation efforts. She attributed part of the success to media coverage that drew attention to the problems associated with horseshoe crab harvesting. "We just feel very proud of getting to this point where they believe they can still do their business, but we are able to protect this bird that really needs these eggs," Wannamaker said. "I think this started with the news coverage, and then people got interested and local organizations got concerned and then it all went from there."