[Letter to Jacob John from Jon Cohen]

TO: DR. JACOB JOHN
FROM: JON COHEN
September 9, 1992
Dear Dr. John,
I am writing a story for Atlantic Magazine about the value of
adding IPV to the OPV schedule in the global program to eradicate
poliovirus. Several people I've interviewed have referred to your
work, and I would like to find out what you think. (So far, the
people I have interviewed include D.A. Henderson, Bill Foege,
Harry Hull, Peter Patriarca, Jonas Salk, Ed Trainer, Philippe
Stoeckel, Stanley Plotkin, and Ciro de Quadros.) I tried to reach
you by phone several times a few weeks ago but you were not in.
Because of the time difference and the poor telephone connection,
I thought it might be easier if I faxed my questions:
1. Have you done studies with IPV? Have you compared IPV and OPV
efficacy? OPV-IPV to OPV alone? If so, what have you found?
Specifically, what are the take rates for the three types of
poliovirus? Have you looked at herd effects with each vaccine?
2. Have you compared excretion of virus in OPV- and IPVvaccinated (or doubly vaccinated) people? Have you looked for
virus in contacts? If so, what have you found?
3. What do you think of the proposal to add IPV to the schedule?
4. I've been told that you are heading a WHO committee evaluating
whether a trial should be done to answer some of the questions
I've listed above. Do you think such a trial is necessary? How
long do you think it would take? If the results were positive,
how long do you think it would take to actually begin vaccinating
with IPV?
5. Why didn't India go forward with plans to produce DPT-eIPV incountry in collaboration with Pasteur-Merieux? Was WHO at all
involved with that decision?
6. I've been told that while India officially favors OPV, its
physicians have recommended IPV use. Is this true? Why the
discrepancy?
7. D.A. Henderson maintains that adding IPV to the schedule will
likely do nothing to stop the transmission of poliovirus in
developing countries. What do you think?

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