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BART ROMBAUT AN. R. ACAD. NAC. FARM.

THE GOLDEN AGE OF POLIOVIRUS RESEARCH

The 1980s were another golden decade for poliovirus research.
The complete genomes of several poliovirus strains have been
sequenced (17, 18) and the capsid structure has been elucidated at
the atomic level (19). By preparing escape mutants, selected by
murine monoclonal antibodies, the four neutralising antigenic sites
of poliovirus could be identified (20, 21). These neutralizing antigenic
sites provoke antibodies in man, protecting us against the disease. It
was found that these neutralising sites were also present on subviral
particles (22), and that these subviral particles could be the active
principle of alternative, new vaccines (23). These particles could even
be cloned in a Saccharomyces cerevisiae inducible expression system
and empty capsids purified from this expression system were shown
to have the same immunogenicity as poliovirus virions (24, 25).
However, none of these alternative vaccines has been further
developed.

THE GLOBAL POLIO ERADICATION INITIATIVE

In may 1988, at its annual meeting in Geneva, the World Health
Assembly, the governing body of the World Health Organization
(WHO), resolved to eradicate polio from the world. After smallpox,
poliomyelitis would be the next disease to be targeted for global
eradication. The global eradication of polio has two components:
(i) halting the incidence of the disease and (ii) the worldwide
eradication of poliovirus. There is only a limited number of diseases
that can be eradicated. Most diseases can only be controlled. The
rationale for polio eradication is:

(1) polio only affects humans, and there is no animal reservoir

(2) an effective, inexpensive vaccine exists (OPV)

(3) immunity is life-long, and

(4) the virus can only survive for a very short time in the
environment.

The polio eradication strategy is based on the premise that
poliovirus will die out when it is deprived of its human host through

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