.
H5N1 Wild Bird Flu Recombining Away From Pandemic Vaccine
Recombinomics Commentary
August 14, 2005
That research showed that the virus sequence is PQGERRRKKR/GL, which is analagous to the sequence of the highly virulent virus found in three species of migratory water birds during the epidemic in May/June on Qinghai Lake (People's Republic of China)(3).
The nucleotide sequences of the PCR fragments of two other parts of haemagglutinin and neuraminidase also showed the highest similarity with the nucleotide sequences of the isolates from infected mountain geese and gulls at the time of the above-mentioned epidemic.
According to the phylogenetic tree, the preliminary data on the neuraminidase structure show that it is practically identical to that of the isolate from bar-headed geese (Anser indicus) from the Qinghai Lake region (People's Republic of China).
The above comments from Russia's OIE supplemental report leave little doubt that the H5N1 wild bird flu sequences from Qinghai Lake in Qinghai, China and Chany Lake in Novosibirsk, Russia are very closely related. The report included a 124 amino acid sequence of HA from a turkey from the village of Suzdalka, Dovolnoye district, Novosibirsk region. The sequence also had the identical cleavage site sequence as well as a polymorphism found in isolates from Japan and South Korea. This polymorphism provide evidence of recombination. Moreover the HA sequence had an addition 3 amino acid changes not seen in other H5N1 isolates.
Thus, the wild bird sequences from Qinghai Lake and Chany Lake are significantly different from the H5N1 sequence being used to develop a pandemic vaccine. The titers have been low and 180 micrograms of virus are required for a modest response against the immunizing H5N1. This response indicates that the vaccine will have little benefit against the H5N1 wild bird strains.
The Vietnam isolate was distributed worldwide for development of a pandemic vaccine. Thus, the vaccine planed for use in Russia next month will offer little protection for the H5N1 rapidly spreading in Russia (see map). The rapid spread of the H5N1 wild bird sequences ahead of the migratory period suggests the wild bird versions of H5N1 may soon be spread throughout Asia and Europe, and probably beyond.
This rapid spread of the novel H5N1 wild bird sequences indicates a pandemic vaccine against these sequences should be developed as soon as possible. H5N1 evolves via recombination, so it is likely that the wild bird strains will be strong contributors to an evolved pandemic strain.
Current efforts focused on a single strain are inadequate. The vaccine has a low titer, requires large amounts of virus, and has little utility for the wild bird strain spreading toward Europe.
The pandemic vaccine efforts have clearly been too little too late.
Further delays in the expansion of the vaccine effort are scandalous.
.
Map
Media Resources