A group of chimpanzees formerly used in hepatitis B vaccine research by American scientists have undergone health evaluations at a sanctuary in Liberia, where they are now being cared for after years in laboratory settings. The West African chimpanzees, many of which were captured as infants in the wild, received comprehensive medical checks at the Humane World for Animals’ Second Chance Chimpanzee Refuge, located in central Liberia.
The chimpanzees were involved in experimental research from the 1970s until the early 2000s, with over 400 individuals used in the studies, according to Liliana Pacheco Ricote, director of the sanctuary. Liberia holds the second-largest population of chimpanzees in West Africa, after Guinea, with the species being classified as critically endangered due to their rapidly declining numbers.
Under anesthesia, the animals underwent thorough health assessments including dental exams, X-rays focusing on the heart, lungs, and nervous system, as well as blood tests. The sanctuary also provided booster vaccinations and trimmed their fingernails as part of ongoing care. The chimpanzees now primarily reside on a group of mangrove forest-covered islands that form part of the sanctuary. Since 2015, the organization has taken permanent responsibility for 60 chimpanzees that remained after the conclusion of the research program.
Sanctuary veterinarian Belen Perez Hernando emphasized the importance of these health checks as part of providing long-term care tailored to the chimpanzees’ needs as they age. Liliana Pacheco Ricote acknowledged that many of the animals show signs of the pain and distress experienced during their years of laboratory experiments, although the full extent of the impact remains unclear pending the completion of the ongoing evaluations.
The experiences of these chimpanzees highlight broader concerns about the use of animals in research. Dr. Mark Ofua, a veterinarian and representative for the Wild Africa conservation group in West Africa, noted that animals subjected to experimental research often endure confinement, social disruption, and lasting physical and psychological harm. He called for stricter regulations governing animal research, citing reviews that found many chimpanzee experiments did not significantly contribute to advancing treatments for human diseases.
Despite the challenges faced, sanctuary staff expressed a commitment to providing the chimpanzees with a dignified second chance at life. Ricote stated that witnessing the animals’ recovery and ability to live in a more natural and caring environment offers a sense of fulfillment after their years of suffering. The sanctuary plans to continue health monitoring for all the chimpanzees in its care to better understand their needs and improve their well-being.