Nov. 24 (Bloomberg) -- Adrian Gibbs, the virologist who said in May that swine flu may have escaped from a laboratory, published his findings today, renewing discussion about the origins of the pandemic virus.
The new H1N1 strain, which was discovered in Mexico and the U.S. in April, may be the product of three strains from three continents that swapped genes in a lab or a vaccine-making plant, Gibbs, and fellow Australian scientists wrote in Virology Journal. The authors analyzed the genetic makeup of the virus and found its origin could be more simply explained by human involvement than a coincidence of nature.
Their study, published in a free, online journal reviewed by other scientists, follows debate among researchers six months ago, when Gibbs asked the World Health Organization to consider the hypothesis. After reviewing Gibbs’ initial three-page paper, WHO and other organizations concluded the pandemic strain was a naturally occurring virus and not laboratory-derived.
“It is important that the source of the new virus be found if we wish to avoid future pandemics rather than just trying to minimize the consequences after they have emerged,” Gibbs and colleagues John Armstrong and Jean Downie said in today’s eight- page study.
Gibbs and Armstrong are on the emeritus faculty at the Australian National University in Canberra and Downie is affiliated with the Centre for Infectious Diseases and Microbiology Laboratory Services at Sydney’s Westmead Hospital, according to the study.
While the exact source of the new H1N1 strain is a mystery, their research has “raised many new questions,” they said. The authors compared the genetic blueprints of flu strains stored in the free database Genbank and found the pandemic virus’s nearest ancestors circulate in pigs.
While migratory birds may have acted as conduit for their convergence, human involvement in bringing them together is “by far the simplest explanation,” Gibbs said in a telephone interview today.
Gibbs wrote or coauthored more than 250 scientific publications on viruses, mostly pertaining to the plant world, during his 39-year career at the Australian National University, according to biographical information on the university’s Web site.
“Knowing Adrian Gibbs, he will have thought through it pretty logically and come to that conclusion,” Lance Jennings, a clinical virologist with Canterbury Health Laboratories in Christchurch, New Zealand, said in a telephone interview. “It’s up to someone else to try and prove it or disprove it.”
The swine-origin influenza A (H1N1) virus that appeared in 2009 and was first found in human beings in Mexico, is a reassortant with at least three parents. Six of the genes are closest in sequence to those of H1N2 'triple-reassortant' influenza viruses isolated from pigs in North America around 1999-2000. Its other two genes are from different Eurasian 'avian-like' viruses of pigs; the NA gene is closest to H1N1 viruses isolated in Europe in 1991-1993, and the MP gene is closest to H3N2 viruses isolated in Asia in 1999-2000. The sequences of these genes do not directly reveal the immediate source of the virus as the closest were from isolates collected more than a decade before the human pandemic started. The three parents of the virus may have been assembled in one place by natural means, such as by migrating birds, however the consistent link with pig viruses suggests that human activity was involved. We discuss a published suggestion that unsampled pig herds, the intercontinental live pig trade, together with porous quarantine barriers, generated the reassortant. We contrast that suggestion with the possibility that laboratory errors involving the sharing of virus isolates and cultured cells, or perhaps vaccine production, may have been involved. Gene sequences from isolates that bridge the time and phylogenetic gap between the new virus and its parents will distinguish between these possibilities, and we suggest where they should be sought. It is important that the source of the new virus be found if we wish to avoid future pandemics rather than just trying to minimize the consequences after they have emerged. Influenza virus is a very significant zoonotic pathogen. Public confidence in influenza research, and the agribusinesses that are based on influenza's many hosts, has been eroded by several recent events involving the virus. Measures that might restore confidence include establishing a unified international administrative framework coordinating surveillance, research and commercial work with this virus, and maintaining an registry of all influenza isolates.