[新聞] WHO to decide fate of smallpox stocks
標題: WHO to decide fate of smallpox stocks
Heated debate expected next week over when to destroy lab samples of deadly
virus.
Health ministers from the World Health Organization's (WHO's) 193 member
states will next week debate when to destroy the two last known remaining
stocks of the virus that causes smallpox, a scourge that was eradicated in
1980.
Many scientists argue, however, that the variola stocks should be maintained,
perhaps indefinitely. The stocks are helping the development of new
countermeasures such as drugs, vaccines and diagnostics in case smallpox
should reappear, and may also allow researchers to explore the impact of
smallpox on the human immune system, providing insights into other diseases
such as AIDS.
After smallpox was eradicated, the WHO quickly reached a consensus that
existing lab stocks should be destroyed to eliminate the risk of accidental
release, and a deadline of 1993 was set. By 1984, stocks from 74 laboratories
had been either destroyed or transferred to the two WHO-sanctioned
repositories – the US Centers for Disease Control and Prevention in Atlanta,
Georgia, and the Russian State Research Center of Virology and Biotechnology
in Koltsovo, near Novosibirsk.
Many developing countries that would probably bear the brunt of any
accidental release have long backed the destruction plan. But the WHO has
repeatedly pushed back the deadline under pressure from developed countries,
including the United States, who want to continue research on the virus. At a
meeting in Geneva, Switzerland, next week, the United States will seek a
further reprieve for the stocks.
The disagreement stems from big differences in the perception of risks and
benefits among many developed and developing countries, says David Heymann,
chairman of the board of UK Health Protection Agency, and former Assistant
Director-General for Health Security and Environment at the WHO, where he
also oversaw efforts to eradicate polio.
Many poorer countries view smallpox research as a potentially dangerous
luxury, he explains, whereas developed countries' main concern is to continue
research that would protect against the consequences of a deliberate release
by rogue states or terrorists, who may have access to undeclared stocks.
"There are adequate, if not overwhelming, reasons to be concerned that the
two repositories that are under debate right now are not the only places in
the world where live smallpox virus still exists," says Nils Daulaire,
director of the Office of Global Health Affairs at the US Department of
Health and Human Services, and head of the US delegation to the Geneva
meeting. "As long as that possibility exists, I think the world is a much
safer place with the development of these countermeasures." The United States
remains committed to ultimate destruction of the stocks, he adds: "If we knew
for a fact when we would have these smallpox vaccines and antivirals fully
developed and fully licensed, we would have no problem with a clear timetable
for destruction."
Many scientists also argue that destroying the stocks would do little to
protect the world from smallpox, because it is now possible to recreate the
virus from its genome, which was sequenced in 1994. Only a handful of labs
have the skills and resources to do so, but it is likely to become easier
over time as DNA-synthesis machines become faster and cheaper.
Pox progress
The WHO last considered destroying the lab stocks in 2007, when it postponed
the decision pending an assessment of whether more research on the live
variola virus was needed. The WHO has emphasized that science alone cannot
justify retention, and that any research must have tangible public-health
benefits.
The review panel convened to address the matter was not asked to assess
whether the stocks should be destroyed, although its report, published last
December, made a strong case for continued research. Perhaps reflecting the
debate's complex politics, the WHO asked a separate expert panel (AGIES),
made up largely of public-health experts from developing countries, to review
the scientific report and recommend whether further research was warranted.
They argued that it is largely not.
The AGIES panel's "perception was flavoured by its public-health perspective
on scientific arguments", says Grant McFadden, a poxvirus researcher at the
University of Florida in Gainesville and a member of the scientific review
panel. He believes that the risks of accidental release are low compared with
the scientific and public-health benefits.
McFadden points out that the past decade has seen much progress in smallpox
research, in particular the development of two new drugs (which have not yet
been licensed). Current vaccines are effective, but are unsuitable for people
with compromised immune systems, including people with HIV.
The key problem for research on smallpox is that there is no good animal
model for the disease. "Human smallpox doesn't cause disease in non-human
primates that resembles the human disease," says McFadden. Infections of
other poxviruses in their natural hosts provide more realistic, yet still
imperfect, models.
Because clinical trials of new drugs and vaccines for the disease are
impossible, the US Food and Drug Administration and other regulatory agencies
currently demand that vaccines and drugs show efficacy in animals challenged
with live smallpox. The WHO's AGIES panel argued, however, that the
regulatory system should be changed to allow licensing of smallpox drugs and
vaccines on the basis of multiple animal surrogates, using various poxviruses
in their natural hosts. The only remaining need for the live virus was to
test the efficacy of drugs in vitro, it said.
But the entire debate over regulatory needs may be moot, says Jonathan
Tucker, a biosecurity researcher at the Federation of American Scientists in
Washington DC. Any likely use of drugs or vaccines against smallpox would
come under emergency regulatory provisions that allow the use of treatments
that have not been completely tested.
The outcome of next week's meeting is difficult to predict. WHO resolutions
are not legally binding under international law, so the body usually seeks to
pass them by consensus, with very few going to a vote. "I'm very confident
that at the end of the day there will be a resolution accepted by consensus
that will maintain a programme of research and that will call for a review of
progress in a number of years," says Daulaire.
If a vote did result in a decision to destroy the stocks, the United States
and Russia would be left in a difficult position, says Tucker. They could
comply with the WHO's request or defy it – or perhaps, more worryingly, they
could be tempted to maintain their stocks covertly.
新聞來源: (須有正確連結)
http://www.nature.com/news/2011/110513/full/news.2011.288.html
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大意就是最近科學界又要召開會議
決定是否完全消滅天花病毒
大部分的國家都表示贊同
因為不想承擔意外感染的風險
由其發展中國家的醫療資源較薄弱
懼其被用於恐怖攻擊,故特別反對
不過還是有些國家堅持留下來就做科學研究
--
I remember a Senator once asked me 'when we talk about CIA why we never use
the word the in front of it.' And I asked him 'do you put the word the in
front of god?' -- The Good Shepherd
--
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