Pearl Kendrick | Grace Eldering

Dr. Pearl Kendrick and Dr. Grace Eldering, working at the Michigan Department of Health in the United States, developed a more effective whole-cell pertussis (whooping cough) vaccine during the 1930s. Their key breakthrough work occurred between 1932 and 1937.

The more effective whole-cell pertussis vaccine they developed was tested in one of the first large-scale, controlled clinical trials of a vaccine, starting in 1934, with wider implementation beginning in 1938.

1933–1934: Kendrick & Eldering Begin Research (USA)

• Dr. Pearl Kendrick and Dr. Grace Eldering at the Michigan Department of Health begin systematic work on pertussis vaccines

• Develop a formalin-inactivated whole-cell pertussis vaccine

• Emphasize rigorous laboratory methods and clinical evaluation

1936–1938: First Controlled Clinical Trials

• Kendrick and Eldering conduct one of the world’s first double-blind, controlled clinical trials (with the help of Dr. Loney Clinton Gordon)

• Over 5,800 children in Grand Rapids, Michigan, are enrolled.

• Results show high efficacy: around 89% protection against clinical pertussis.