WHO Urged to Release All Sequestered Sequences of H5N1

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ePT--the Electronic Newsletter of Pharmaceutical Technology

Recombinomics (Pittsburgh, PA) is again urging the World Health Organization to fully release all H5N1 avian influenza sequences, claiming their release would improve the selection of vaccines by helping scientists to identify the origin of the isolates and predict sequence changes.

Recombinomics (Pittsburgh, PA, www.recombinomics.com) is again urgingthe World Health Organization to fully release all H5N1 avian influenzasequences, claiming their release would improve the selection ofvaccines by helping scientists to identify the origin of the isolatesand predict sequence changes. Currently, only the sequences from oneH5N1 patient in Indonesia have been made public. The selection of thisisolate led to the development of the pandemic vaccine in the UnitedStates. Meanwhile, sequences from the outbreak of the largest and mostfatal cluster of bird flu in Indonesia and early human cases inIndonesia remain sequestered at WHO's private database.

The company has pushed the release of the sequestered sequences sinceMarch 2006, when it argued that "considering the hundreds of millionsthat will likely be spent in manufacturing a 'new' vaccine againstH5N1, additional research and analysis by the scientific communitywould be both warranted and potentially beneficial."

"Release of recent H5N1 sequences is essential," said Recombinomicspresident Henry Niman, PhD. "These sequences provide a roadmap of whereH5N1 has been and where it is going. These data are critical foreffective vaccine development."

Niman's research has identified recombination as the underlyingmechanism driving rapid genetic change. The company has developed apatent-pending sequence analysis for this purpose, but "the usefulnessof the approach is enhanced by a robust database of all eight genesegments," argues Niman. "Data from an H5N1 infected cat as well asother hosts in Indonesia and worldwide would also enhance the analysis,adding to the need for the release of all sequestered H5N1 sequences."

The H5N1 virus is known to recombine frequently and evolve rapidly.Vaccinologists point out that vaccines against future sequences aremore effective than vaccines against sequences that have alreadyemerged. Scientists at Recombinomics believe at least three distinctH5N1 strains are circulating among humans residing in Indonesia. Themost common strain, which is similar to the publicly available sequencehas a novel cleavage site that has not been reported in Indonesianpoultry or elsewhere. A second strain has a wild-type cleavage sitethat is "associated with increased virulence in mammals and an almostuniversal fatality rate in humans." The third strain has been linked tothe large outbreak cluster in north Sumatra and is amantadine (anantiviral) resistant.

Indonesian officials have reported 44 human cases of H5N1 infectionsand 34 deaths as of late May, the most of any other region. The sourceof the outbreak in Sumatra earlier this year, involving seven membersof an extended family, is still unknown and currently underinvestigation.