THE ROCKEFELLER UNIVERSITY

pro bono humani generis
1230 YORK AVENUE - NEW YORK, NEW YORK 10021-6399

Joshua Lederberg
UNIVERSITY PROFESSOR

April 21, 2000
oe

Dr Walter Dowdle

Ctr Dis Control & Prevent

Natl Immunizat Program

Vaccine Preventable Dis Eradicat Div
Tech Serv Branch,

Atlanta, GA 30333 USA.

Dear Walter

I was pleased to see the reports on anticipatory precautions for the "post-polio" era. If I could
expect universal compliance and Nature’s cooperation I’d be even more reassured. (I’ve not
yet seen the current B-WHO).

At minimum it’s time to start moving to drafting and negotiating formal treaty agreements
that would make it a crime under international law to preserve unregistered polio, and an
undertaking that code in domestic law of each country. I do not believe we are anywhere
close to that in regulations adopted by WHO. With all the public fuss we’ve seen about
smallpox, I am sure it will be an irresistible temptation for some rogues to keep some polio in
their freezers, for purposes who knows what.

Epidemic Polio itself evolved (into at least 4 strains) within the human species; what can we
say of the odds of re-evolution? What is known of DNA homologies and immunological
cross-reactions of polio strains with other picornaviruses? Has there been any systematic
search for these (not necessarily associated with frank disease) in other fauna?

Yours

pte

Josh