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. 2020 Apr 20;10(4):391–401. doi: 10.1016/j.jceh.2020.04.006

Table 2.

Human Experiments on Viral Hepatitis in Children at Willowbrook. Results of Seven Trials Which Pointed to Existence of Two Hepatitis Viruses are Defined. The Clinical, Epidemiological and Immunological Characteristics of MS-1- and MS-2–Related Diseases are Shown.

Trials Date Inoculum Route Subjects Results
First Trial [F T] Sept 23, 1964 WSP-5 Oral 13 NAS [11 EI & 2 C] H=10 of 11 EI (6 had IH). AH = 1 of 2 C
IP = 30–36 d in 6, 51–58 d in 3, 125 d in1
Second Trial [S T] March 26, 1965 WSP-5 IM 13 FT [10 EI & 3 C] H = 6 out of 10 EI (4 out of 6 had SA:- Sch, Mas, Wac, Mir]. IP = 38–102 d
Third Trial [T T] Nov 22, 1965 MS-1 IM 14 NAS [8 EI & 6 C] H = 7 of the 8 EI (1 had IH); IP = 31–53 d
H = 6 of 6 C (I had IH); IP = 46–85 d
Fourth Trial [Fi T] August 24, 1965 MS-2 IM 14 NAS [9 EI & 5 C] H = 7 of 9 EI (1 had IH); IP = 41–69 d
AH = 2 of 5 C; IP = 155–231 d
Fifth Trial [Ft T] Feb 17, 1966 MS-2 (Ham) +
μ-globulin
Oral 9 NAS [6 EI & 3 C] AH = 5 of 6 EI; IP = 64–209 d
All 3 C had no hepatitis
Sixth Trial [Si T] May 27, 1966 MS-2 (Ham & Pel) Oral 6 NAS AH = 5 of 6 EI; IP = 88–108 d
Seventh Trial [St T] March 28, 1966 MS-1 IM 16 [8 T T & 8 Fi T] H = 0 of 8 T T (Immunity vs. MS-1)
H = 8 of 8 Fi T (no immunity vs. MS-2))
MS-1 Hepatitis
MS-2 Hepatitis
Infectious hepatitis Serum hepatitis
Incubation Period 15–50 days 43–180 days
Transmission Oral + Parenteral Oral + Parenteral (IP longer with oral) (Si T vs. Fi T)
Contact spread High (T T) Low
Transaminitis Sharp and short lasting Gradual and prolonged
Immunity No cross immunity between MS-1 & MS-2. Homologous immunity following MS-1 & MS-2 infections.
Clinical profile Indistinguishable
 IH/AH 10/19 6/21
 Bilirubin levels 1–3 mg/dl 1–3 mg/dl
 Duration icterus 1–10 d (5d) 1–10 d (5d)
 Weight gain 0.9–3.6 kg (25 weeks) 1.8–2.7 kg (30 weeks)
Krugman et al JAMA 1967;200:365–373.

WSP-5= Willowbrook Serum Pool from 27 patients collected 3–7 days before jaundice; NAS= Newly Admitted Subjects; EI = Experimentally Infected; C=Controls; IP= Incubation Period; SA= Second Attack; H= Hepatitis; IH= Icteric Hepatitis; AH = Anicteric Hepatitis; MS-1 = Sample of subject Mir immediately prior to First Attack; MS-2 = Sample of subject Mir immediately before the Second Attack.