Biologics Regulation and ResearchThe People and Work of Buildings 29 & 29A

At the same time, a “French strain” was discovered in Dakar, Senegal. Andrew Watson Sellards from Harvard and his team discovered the virus survived freezing, allowing transport of infected liver tissue. There were some crude vaccines using formalin and phenol-preserved liver tissue, but with uncertain results. Max Theiler knew they needed a better host, so he then inoculated mice intracerebrally and found that the virus grew well. He created the first attenuated strain of yellow fever, but with increased neurotropism.

The Rockefeller Foundation was involved in research in West Africa. Tragically, many of the lead researchers died of yellow fever from the 1925 expedition, but they were able to infect rhesus monkeys and therefore could remove the virus to the lab and study it. They discovered that serum from immune humans protected monkeys against infection, immune serum from South America protected against the African virus, and the killed virus would not confer immunity.