LIVE POLIO IRUS VACCINES

11. FURTHER EXPERIENCES WITH ORAL POLIOMYELITIS
VACCINES IN MINNESOTA
1. A Comparison of Monovalent and Trivalent Vaccines
2. Observations on Pharyngeal Recovery of Poliovirus and Viremia*
HERMAN KLEINMAN, M.D., ROBERT N. BARR, M.D., HENRY BAUER, PH.D.,
ANNE C. KIMBALL, PH.D., MARION K. COONEY, M.S., JACOB E.
BEARMAN, PH.D., AND WAYNE E. MATHEY, M.D.t
DR. KLEINMAN (presenting the paper): You
will notice that the paper I am about to present
has two subtitles: one, "A Comparison of Monovalent
and Trivalent Vaccines"; and two, "Observations
on Pharyngeal Recovery of Poliovirus and
Viremia."
In fact, it might actually have a third one,
which I would like to put in parentheses, namely,
that it is a study that did not quite come off. The
reason for this is that as we went along in this
work we found that some of the Type 2, or
labeled Type 2, monovalent vaccine had gotten
into them some Type 1 poliovirus vaccine, as a
contaminant.
True enough, the amount of Type 1 vaccine
that we found in our Type 2 was small, of the
magnitude of five tissue-culture doses; nevertheless,
some of our participants did actually get two
doses of Type 1 vaccine, even though the adventitious
dose was quite small.
Now, I can explain how we first suspected,
then proved, and finally were assured, that this
contaminant was a vaccine virus and not a wild
virus, but I shall leave that for the discussion
period, or for private conversations with any of
you, if you wish.
Therefore, as I go on, when I use the term
* This is one of a series of studies being reported.
Supported in part by grants from the Sister Elizabeth
Kenny Foundation and the Lederle Laboratories, Division
of the American Cyanamid Company, Pearl
River, New York.
t Dr. Kleinman, Dr. Barr, Dr. Bauer, Dr. Kimball,
Miss Cooney (Minnesota Department of Health); Dr.
Bearman (School of Pablic Health, University of
Minnesota); and Dr. Mathey (formerly, Medical
Officer, U.S. Public Health Service).
341
monovalent, will you kindly make the proper
mental correction in your minds, particularly with
respect to Types 1 and 2.
Permit me to go ahead and present the data
with a minimum of minutiae and without any
speculation. I think that you will find that they
are interesting, even though they did not strictly
accomplish their primary intended purpose.
INTRODUCTION
Previous experience has convinced these
authors that the Cox strains of attenuated polioviruses
are good antigens.' Equally convincing
and impressive was the ease of administration
afforded by the oral route. The ability to feed
the three types of the vaccine viruses simultaneously,
instead of separately at intervals,
could only enhance the existing operational and
administrative advantages of such an immunizing
agent.
Cox has published the evidence that led him
and his associates to the belief that simultaneous
feeding was a practical possibility. He has also
presented evidence to show that such a trivalent
agent is effective. 2 One of the objectives of this
study was to use the trivalent vaccine in a selected
group and to compare its action to the effect of
the monovalent vaccines used in members of a
comparable group.
Also, since the total group was of such a
special character (University students and their
children), it was deemed likely that they would
cooperate in some studies directed toward discovering
some of the facets of the vaccine viruses'