Press Release WHO/48
26 June 1998
AS POLIO RETREATS, VIRUSES IN LABS POSE BIGGEST RISK TO WORLD POPULATION
With the World Health Organization's (WHO) Global Polio Eradication Initiative on target, the Organization is preparing for "life after eradication" by urging its 191 Member States to draw up a list of all polioviruses kept in laboratories and other medical institutions and to ensure safety regulations.
Ten years after the start of the World Health Organization's Global Polio Eradication Initiative, reported case numbers have plummeted from 35,000 a year to around 4,000. Polio is now endemic in only 52 of the world's 215 countries or territories that report to the WHO. Provided the Initiative receives enough fundingit needs US$400 million to cover a shortfall over the next three yearsit should attain its objective to eradicate polio by the year 2000. However, as vast swathes of the planet become free of the disease,* (after virus importation) the second biggest risk to countries in these areas is the escape of poliovirus from a laboratory. In fact, after global eradication of polio, immunization against the disease will eventually stop and the population of the entire world will face this risk.
Dr Jong Wook Lee, Director of the WHO's Global Programme for Vaccines and Immunization (GPV), which is spearheading the eradication initiative, is reassuring: "The global call will go out for all nations to cease immunization only when it is certain that the virus is no longer around to cause disease," says Dr Lee. "When no further cases of polio are occurring, the only remaining viruses will indeed be in labs. These viruses will have to be hunted down in whatever lab they may be lurking and will then have to be confined to a few high-security facilities."
Dr Bruce Aylward, GPV Medical Officer in charge of the day-to-day running of the polio initiative, says: "We have to avoid a replay of what happened when smallpox was eradicated." In 1977, he notes, less than a year after the last case was found (in Somalia) of naturally acquired smallpox, a death occurred in the United Kingdom as a result of a smallpox virus escaping from a nearby laboratory. "But polio is not a highly visible disease like smallpox, so it could spread silently among an unprotected population, creating a public health tragedy of global proportions."
Hence, the urgency to plan now for the hunting down and ultimate high-security "containment" of polioviruses. This week, the WHO sent out for comment to governments of all its Member States a proposed "Global Action Plan and Timetable for the Safe Handling and Maximum Laboratory Containment of Wild Polioviruses and Potentially Infectious Materials." Copies were also sent for comment to research institutions, professional scientific societies and other concerned groups and individuals throughout the world.
The proposed plan covers three phases: before eradication, after eradication and after cessation of polio immunization.
Although it is intended that the final plan will officially go into effect on 1 January, 1999, the first, pre-eradication, phase should begin before the end of this year. This phase calls for all countries to identify and draw up a list of laboratories where wild poliovirus (as distinct from the live, attenuated poliovirus used to make the oral polio vaccine) might be present. Laboratories identified as likely to be harbouring poliovirus will have to set up a minimum level of safe handling of infectious or potentially infectious materials (an enhanced biosafety level-2, or BSL-2/polio) and should keep the virus under lock and key.
Such laboratories might be in vaccine manufacturing facilities, hospitals, universities, public health institutions, and so on. Many of them will be aware of the polioviruses they are holding for research or other purposes. Some, however, may fail to appreciate the possibility of poliovirus being lodged in other stored materials, particularly stool specimens that were collected in places and at times when polio was occurring.
The search will target not just the wild virus itself, but also viral strains that have been genetically engineered from poliovirus sequences, and, of course, any cells that are infected with these strains or their derivatives.
The second, post-eradication, phase will start one year after a wild poliovirus was last detected. At that time, laboratories with materials containing or likely to contain poliovirus will need to choose whether to transfer their infectious materials to maximum (BSL-4) biosafety facilities designated by the WHO or to inactivate or destroy the suspected materials.
Further into the future, the third phase will begin as soon as immunization with oral polio vaccine ceases worldwide. At that point in time, all viruses, whether wild or vaccine-derived, will have to be properly contained.
WHO invites wide review and comment on the proposed plan. All countries will need to sign onto the final globally coordinated plan to make sure that eradication of the disease will be followed by eradication of the risk of its resurgence.
* The Western hemisphere was declared free in 1991, the Western Pacific has been free for the past 15 months and Europe is almost free.
For further information, journalists can contact Mr Valery Abramov, WHO, Geneva. Telephone (+41 22) 791 25 43; Fax (+41 22 ) 791 48 58. E-Mail: firstname.lastname@example.org
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