According to Public Health experts, we are in the middle of a global outbreak of whooping cough. Health services across Aotearoa New Zealand are responding to this nationwide epidemic among mostly our youngest pēpi, with 1,232 cases notified since the onset of the epidemic (from 19 October 2024 to 10 January 2025) and 101 cases hospitalised. Pertussis can last up to three months and is sometimes referred to as the ‘hundred day cough’. Around 50% of pēpi who catch whooping cough before the age of 12 months need hospitalisation and 1 or 2 in 100 of those hospitalised pēpi die from the infection. "The best protection for infants is for their mother to be vaccinated during pregnancy," says Dr Susan Jack, National Clinical Director, Protection, at Health New Zealand | Te Whatu Ora. For adults, New Zealand has a combined pertussis and tetanus vaccine.
Did you know that the vaccine for whooping cough used today was developed by three women? Drs. Pearl Kendrick (1890-1980) and Grace Eldering (1900-1988) along with their lab technician and chemist Loney Clinton Gordon (1915-1999) deserve recognition for their ground-breaking work.
French researchers first described Bordetella pertussis as the causative agent of whooping cough in 1906. By the 1920s, pertussis had claimed the most lives of children each year, more than did each of the childhood diseases of diphtheria, scarlet fever, and measles. Pearl Kendrick of New York and her laboratory partner Grace Eldering of Montana worked together after hours on a research project at the Bureau of Laboratories for the Michigan Department of Health. The two doctors recruited Loney Clinton Gordon, a dietician, as a lab technician. Together the three women devised a program of research, conducted lab experiments, did countless field tests, and ultimately succeeded in growing pertussis (the causative) in a medium of sheep’s blood. Gordon had identified sheep blood as the key to the process of incubating the culture in petri dishes in the laboratory. They then began inoculating area children, controlling the population for research purposes. In 1940 the State of Michigan began producing and distributing the vaccine, which virtually ended the incredible toll of whooping cough deaths. Gordon, Kendrick and Eldering developed an opacity standard by which the industry could assure uniformity in judging the concentration of the organisms in the product. In 1946, the United States adopted this standard; in 1958, the World Health Organization designated it as the international standard.
Although the American medical community readily adopted this new whooping cough vaccine, the editor of the British Medical Journal expressed skepticism, arguing that none of the American studies used proper control groups and that their own trials had shown pertussis vaccines developed elsewhere to be ineffective. David Evans of the British Medical Research Council and J.S. Wilson of the London School of Hygiene used Kendrick's serum with their next series of studies in the 1950s with success. Kendrick and Eldering later successfully combined shots for diphtheria, whooping cough, and tetanus into a single DPT shot, a forerunner of the vaccine that now routinely protects 85 percent of the world’s children. In New Zealand, the first formal immunisation schedule for the delivery of triple (DTP) vaccine was drawn up in November 1960.
It's estimated that today, the vaccine saves half a million lives annually. Read more about Kendrick, Eldering and Gordon and their international impact in the essay by Carolyn G. Shapiro-Shapin here.
To read more articles from The Circular (January-February 2025) issue 650, click on the tag below.