Christopher Leung Papers
From The Long Sepsis, an encyclopedia of a world that didn't happen
The Christopher Leung Papers are a manuscript collection held in the Modern Manuscripts section of Cambridge University Library, comprising approximately fifteen thousand pages of laboratory notebooks, correspondence, departmental records, and statistical analyses produced between 1968 and 1995. They document the research programme in serum therapy development at the Infectious Disease Research Centre in Cambridge, where Leung served as principal investigator, and constitute the most detailed surviving record of clinical serum trial methodology in the 1970s and 1980s.
The collection is organized in four principal sections. The first contains Leung's personal laboratory notebooks from 1968 to 1984, written in both English and Cantonese, detailing the daily conduct of animal immunization protocols, serum harvesting procedures, and potency assays. The second section holds correspondence with Dorothy Umezaki at the Infectious Disease Research Centre and with researchers at the Pasteur Institute, the Institute for the History of Bacteriology, and the International Serum Registry, spanning the critical period 1974-1982 when the Halloway-Umezaki method was moving toward clinical licensing. The third comprises statistical worksheets and preliminary analyses for published trials, including calculation sheets for the adaptation of Kaplan-Meier survival methods to serum therapy data — marking some of the earliest systematic application of those methods to passive immunotherapy outcomes. The fourth section contains unpublished departmental reports and inspection records from the Infectious Disease Research Centre's animal facilities, revealing the infrastructure of serum production in this era.
The papers entered Cambridge University Library in 1998, three years after Leung's retirement, through the intermediation of the Centre's director. The library initially catalogued them as a single series; systematic finding guides were not prepared until 2004, when a research fellow at the Institute for the History of Bacteriology in Berlin requested access to the trial data. The delay reflected a general institutional uncertainty in the 1990s about whether laboratory records from a research programme now fully superseded by serum pharmacology held sufficient historical interest to warrant detailed processing. A donation deed from 1997, held with the papers, stipulates that access to unpublished clinical data remain restricted until 2025, a condition the university has observed, though researchers with institutional approval have been permitted to examine anonymized statistical summaries since 2010.
The papers are central to three distinct historiographical questions. The first concerns the actual timeline of serum therapy's clinical validation: whether the Halloway-Umezaki method's rapid regulatory approval in 1979 reflected genuine efficacy data or institutional momentum and the absence of alternative treatments. Leung's raw trial numbers have been cited to support both interpretations; one analysis argues his septicaemia mortality reductions of 31 percent over historical controls represent genuine breakthrough, while another contends they fall within the statistical noise of small trials and reflect selection bias toward less severely ill patients.
The second concerns the Kaplan-Meier estimator's adaptation to serum therapy. Leung's worksheets show him working through the calculation by hand in 1975-1976, apparently independently of the parallel efforts at other centres. Whether he should receive priority credit for the adaptation remains unsettled among medical historians; the papers provide evidence of his working method but not of priority correspondence or publication timing.
The third involves the animal welfare standards in serum production. The centre's inspection reports, which Leung preserved with apparent completeness, document regular violations of the Geneva Sanitary Bureau's 1960 housing standards for immunized cattle and horses — overcrowding, inadequate feed rotation, and a notable brucellosis outbreak in 1982. Leung's own notes express frustration with the Centre's budget constraints but do not record any formal objection to the conditions. Animal welfare historians have used the papers as evidence of the systemic pressure to prioritize serum yield over animal care during the critical period when serum therapy was competing for institutional and funding legitimacy against the still-dominant azo drugs.
References
- 1.Christopher Leung: Notebooks and Correspondence, 1968-1984
- 2.Cambridge University Library
- 3.Modern Manuscripts section
- 4.Finding Guide (2004), prepared by Sarah Chen and Michael O'Rourke
- 5.The Development of Serum Therapy in Post-War Britain: The Infectious Disease Research Centre, 1968-1992
- 6.by Adrian Morris, Cambridge University Press, 2008, pp. 145-189
- 7.Kaplan-Meier Methods in Clinical Bacteriology: Origins and Early Applications
- 8.by Paul Kaplan and Dorothy Umezaki, Journal of Medical History, vol. 42, no. 3, 1994, pp. 267-291