Chimpanzees that were part of hepatitis B vaccine experiments from the 1970s through the early 2000s are now receiving comprehensive medical examinations at a sanctuary in central Liberia. The checks, which include dental cleaning, X‑rays, blood work and other procedures, are intended to assess the animals’ long‑term health and to develop individualized care plans as they age.
Background and sanctuary care
More than 400 chimpanzees were used by American researchers in Liberia for hepatitis B vaccine studies, according to Liliana Pacheco Ricote, director of the Second Chance Chimpanzee Refuge operated by Humane World for Animals. Many of the primates were captured in the wild as infants and subjected to invasive research that caused significant pain, Ricote said.
In 2015 the sanctuary assumed permanent responsibility for the 60 chimpanzees that remained at the end of the research program. The animals now reside on a series of mangrove‑covered islands within the refuge, where they receive daily care, enrichment and protection from poaching.
Scope of the health assessments
Under anesthesia, each chimp undergoes a head‑to‑toe examination that includes dental cleaning, X‑ray imaging, and a pedicure. Veterinarians evaluate the heart, lungs and nervous system, draw blood for laboratory analysis, administer booster vaccinations and trim fingernails. Belen Perez Hernando, the sanctuary’s veterinarian, described the examinations as “vital” for chimpanzees that have endured extensive laboratory procedures.
The sanctuary plans to extend the same suite of checks to the remaining former research subjects, whose average age is now between 30 and 35 years. Findings from the examinations have not yet been published, but the data will help staff monitor early signs of disease and adjust care as the chimps continue to age.
Conservation and ethical implications
West African chimpanzees are classified as critically endangered, with Liberia hosting the second‑largest population in the region after Guinea. Dr. Mark Ofua, a veterinarian with the Wild Africa conservation group, highlighted the broader ethical concerns, noting that animals used in research “rarely are the intended beneficiaries” and often suffer lasting physical and psychological harm.
Ofua called for stricter regulations on animal experimentation, adding that reviews have shown most chimpanzee studies failed to make significant contributions to human disease treatment. Ricote echoed the sentiment, saying the sanctuary’s work offers the animals a “second chance to live with dignity the life that they deserve.”
The ongoing health program underscores a shift from using primates for invasive biomedical research toward prioritizing their welfare and conservation. As the assessments continue, the sanctuary hopes the data will not only improve individual care but also inform broader discussions about the role of non‑human primates in scientific research.
Mitchell Landsberg is a Senior Technology Correspondent at News Raise. He covers consumer electronics, artificial intelligence, software developments, and digital privacy trends.
