theory for lab origin of swine flu
By Peter Duveen
PETER'S NEW YORK, Tuesday,
September 22, 2009--The swine flu that is making its rounds throughout
the world has signs it was produced in a laboratory, say two
researchers, although a theory that the virus had been circulating
undetected among swine for some time before jumping to humans has not
been ruled out.
According to a research note circulated by two virologists,
Adrian J. Gibbs and Jean Downie, the signs that point to a laboratory
origin of the swine flu are that it came from three parent viruses, all
from disparate parts of the world, and that the last time these parent
viruses were sampled in pig populations was from eleven to seventeen
Gibbs and Downie contend that the
swine flu's triple parentage would only have been possible with the
breaking of quarantines of infected pigs and their transport in some
combination among three continents. More probable, they say, is that
samples of the viruses had been kept in a laboratory, where they were
allowed to combine. One of the parent viruses was sampled among pig
populations in the United States but never in Europe. Another was
sampled in Europe but never in America. A third was found in Southeast
The fact that the American parent virus had never been sampled in
Europe, nor the European virus in America, Gibbs and Downie say,
is evidence that pig quarantines in
those regions had not been violated.
The other unusual property of the
parent viruses of the swine flu is that the last time each was sampled
was at least eleven years ago, and in one case, 17 years ago. That begs
the question of why all three should have suddenly and simultaneously
combined to form a new virus now, and why they they were not
detected in infected pig populations for so long. The research note
indicates that this can be most easily explained if samples of the
viruses had been sitting in a laboratory refrigerator since they were
last gathered from infected populations more than a decade ago.
The two scientists believe that the
most likely scenario for the emergence of the swine flu was in the
process of preparing a vaccine from the three parent viruses. The
viruses must first be grown in hen's eggs, then chemically sterilized
to prevent them from multiplying in the vaccine recipient. If the
viruses had not been completely sterilized, they could have multiplied
and combined to form today's swine flu, the authors say.
The research note indicates that the
swine flu must have become highly contagious just before it was first
detected in human populations in the Spring. Had it been contagious
earlier, it would
have been detected earlier, explain Gibbs and Downie.
The note mentions a recent paper in
the scientific periodical Nature which proposes that the flu had existed
for a long period of time in pig populations, but had not been detected
because of lax monitoring.
Gibbs and Downie say enough
information is not available to decide between the two hypotheses. The
information needed would be a complete inventory of samples of flu
viruses in laboratories throughout the world, to see if the parent
viruses are among them, along with a check to determine whether there
is any evidence of pig quarantines being compromised. The effort to
determine the origin of the swine flu would be worth it, the authors
"Influenza is a significant and very
costly cause of mortality and morbidity in the human population," say
Gibbs and Downie. "If we wish to avoid new outbreaks rather than
just minimizing the damage they cause, we must better understand what
conditions produce them."
Gibbs, who has published more than 200
scientific papers and is an expert in viral evolution, achieved
notoriety in the Spring when he first put forth his hypothesis that the
swine flu, which emerged in Mexico in April, had a laboratory origin.
Officials of the World Health Organization said they had examined his
hypothesis, but decided the phenomena Gibbs cited in support of his
thesis could be explained in other ways. In an
interview with Peter's New York after the WHO released its findings, Gibbs
said he found the WHO's arguments rejecting his hypothesis
unconvincing. He and Downie have since submitted an updated paper to a
scientific journal, and are awaiting word of its publication.
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