LIVE POLIO IRUS VACCINES

Detection of a "Non-Detectable" Simian Virus
85
TABLE 5.
TESTS FOR NEUTRALIZING ANTIBODY AGAINST VACUOLATING AGENT STRAIN 776 IN HUMAN
AND MONKEY SERA
No. POSITIVE
No. TESTED
DESCRIPTION OF SERA
0/6
12/18
0/1
0/5
0/5
0/6
3/4
Normal African green monkey, diluted 1:5
Normal Rhesus monkey, diluted 1:5
Phil. Serum Exchange, human gamma globulin, lot G50B, diluted 1:50
*Children fed Sabin live oral polio vaccine on six occasions, serum diluted 1:5
*Normal children, serum diluted 1:5
Normal military recruits, serum diluted 1:5
Military recruits given two doses of formalin-killed adenovirus vaccine.
Post-vaccination sample, serum diluted 1:5
* Sera tested for Dr. A. Sabin.
vaccinated persons is not surprising since the
adenovirus seed stocks used to prepare the vaccine
have been found to be contaminated with
the vacuolating virus.
SUMMARY AND COMMENT
The vacuolating virus appears to be a common
and essentially ubiquitous contaminant of
Rhesus monkey-kidney cell cultures, a likely
common contaminant of Cynomolgus kidney cultures,
and a relatively infrequent contaminant
of African green monkey kidney.
The virus appears different from Hull's 3 four
simian virus C.P.E. groups and from Malherbe's
and Harwin's 4 seven agents, based on the distinctive
vacuolating type of cytopathic change
in infected cells. Failure of the vacuolating
virus to cause cytopathic changes in Rhesus or
Cynomolgus monkey-kidney cell cultures further
distinguish the agent from Hull's groups.
Resistance of the virus to ether and failure
of hemagglutination and hemadsorption distinguish
the agent from the Myxoviruses.
The vacuolating agent appears to be just
"one more" of the troublesome simian agents to
be screened for and eliminated from virus seed
stocks and from live virus vaccines. Lack of
antibody response in human subjects fed polio
vaccine containing vacuolating agent suggests
lack of massive proliferation of the virus under
the conditions employed although absence of
human infection to some degree could not be
excluded.
The detection in green monkey kidney of this
common inapparent virus infection of Rhesus
and Cynomolgus monkey kidney represents the
first instance of demonstration of a "non-detectable"
indigenous agent in the monkey-kidney
culture system. Although new to simian viruses
and monkey kidney, it is neither new nor unique
to other viruses and cell culture systems. Demonstration
of the vacuolating agent raises the
question of possible presence of other indigenous
and inapparent monkey kidney agents
which might be detected under different methods
of testing. It also raises the question of the
extent to which proliferation of viruses inoculated
into monkey-kidney cell cultures may be
interfered with owing to the presence of such
inapparent indigenous viral agents.
REFERENCES
1. Rustigian, R., Johnston, P., and Reihart, H.:
Proc. Soc. Exp. Biol. 88:8-16, 1955.
2. Hull, R. N. and Minner, J. R.: Ann. N. York
Acad. Sc. 67:413-423, 1957.
3. Hull, R. N., Minner, J. R., and Mascoli, C. C.:
Am. J. Hyg. 68:31-44, 1958.
4. Malherbe, H. and Harwin, R.: Brit. 1. Exp.
Path. 38:539-541, 1957.
5. Cheever, F. S.: Ann. N. York Acad. Sc. 67:
427-429, 1957.
6. Kalter, S. S.: Bull. World Health Org. 22:
319-337, 1960.
7. Sanderson, I. T.: The Monkey Kingdom. Garden
City, N. Y., Doubleday & Co., Inc., 1957.
8. Hull, R. N.: Personal communication.
9. Hilleman, M. R., Stallones, R. A., Gauld,
R. L., Warfield, M. S., and Anderson, S. A.:
Proc. Soc. Exp. Biol. 92:377-383, 1956.