Primates and Haemophiliacs
Our Closest Friends
Chimpanzees are highly intelligent - but also highly expensive:
"The only way that infectivity for Non-A Non-B hepatitis can be shown (other than human inoculation) is by inoculation in chimpanzees. Since very few of these animals are available, it is difficult to see how every batch treated by this method will have quality control assurance with respect to Non-A Non-B viruses."
Dr J. Craske, PHLS, September, 1981.
"The use of animal models for infectivity study purposes was discussed. Chimpanzees would cost £10,000 per animal test per 6 months. If humans were used it would not be possible to have a "known positive" control. The methods of inactivation available were heat treatment; irradiation or absorption."
SNBTS Minutes of Factor VIII Study Group. March 1982.
"Infectivity of initial batches is tested by injecting the product into Chimpanzees. However, it is stated that it is unlikely that Manufacturers would be able to ensure this form of quality control in all future batches. It is therefore very important to find out by studies in human beings to what extent the infectivity of various concentrates has been reduced. The most clear-cut way of doing this is by administering these concentrates to patients requiring treatment who have not been previously exposed to large pool concentrates."
Professor A.L. Bloom & Dr C.R. Rizza, Letter to Haemophilia Centre Directors. 11 January 1982.
"It was agreed that infectivity was the crucial question and the dilemma over the use of chimps (an endangered species), owl monkeys (information to be supplied by Dr Sommerville when available) and humans formed the basis of a long discussion."
SNBTS Minutes of Factor VIII Study Group. March 1982 .
"I, too, have been told that three chimpanzees which received the Hyland heat-treated Factor VIII had developed hepatitis. This is the sort of information that the Licensing Authority will obviously need when considering applications for product licenses for heat-treated concentrates."
DHSS letter to Manchester RTC, 1 July 1983.
"It is proposed that action continue to investigate the effects of heat, radiation and hydrophobic absorption on FVIII activities. It is also proposed that action be taken to investigate other infectivity assays than chimpanzees, notably owl monkeys, using established colonies. It is also proposed that a model of hepatitis B inactivation be set up using Woodchuck hepatitis virus as the closest analogue. This will require either assay of samples in the U.S. or establishment of a Woodchuck colony here."
SNBTS Minutes of Factor VIII Study Group. March 1982.
"These findings contrast with the absence of non-A, non-B hepatitis in chimpanzees given the same heated concentrate. Thus, clinical studies in first-exposure haemophiliacs are essential for the true evaluation of the safety of new "treated" concentrates." Colombo M., Mannucci P.M. et al. The Lancet, 6 July 1985.
"The high prevalence of NANB hepatitis and the absence of HBV transmission in our subjects are in contrast with the HBV transmission and absence of NANB hepatitis in chimpanzees given the same heated concentrate. These differences indicate that the animal model is not reliable for NANB hepatitis transmission studies and that prospective studies in first-exposure haemophiliacs are essential for the evaluation of the safety of new "treated" concentrates."
Colombo M., Mannucci P.M. et al. The Lancet, 6 July 1985.