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发帖数: 2136 | 1 http://www.recombinomics.com/News/11071001/H3N2_Akita_Vaccine.html
Vaccination Link To H3N2 Death Cluster In Japan Hospital?
Recombinomics Commentary 13:22
November 7, 2010
25 patients and 8 staffs are suffering from influenza now
29 Oct., vaccinated against the flu
31 Oct., a man died(eighties)
2 Nov., 2 men died(sixties, nineties) a woman died(seventies)
4 Nov., a woman died(eighties)
5 Nov., a man died(eighties)
The above comments provide more detail on the H3N2 outbreak in a hospital in
Akita, Japan that killed six patients in six days. These patients had been
vaccinated days prior to the deaths raising concerns that the timing of the
vaccinations may have contributed to the fatal outcomes.
The trivalent vaccine is designed for use prior to infections. The above
timeline raises the possibility that the vaccinations were in response to
the nosocomial outbreak. Elderly patients typically have a poor vaccination
response because of a decline immune system, and therefore may be more
vulnerable to infections shortly after vaccination because their immune
system is taxed by the three targets in the vaccine. In the above outbreak,
it is likely that all victims were infected by H3N2. The H1N1 and
influenza B in the vaccine wouldn’t help mount a response to the live H3N2.
Moreover, the H3N2 in the vaccine may also not help in the short or long
term because the current H3N2 has evolved away from the H3N2 target and an
emerging strain with low reactors has been defined by phylogenetic analysis.
This new strain has been seen in recent sequences from Japan. Low reactors
produce a lower titer, which would significantly impact an elderly
population because they typically produce a marginal response to influenza
vaccinations.
The taxing of the immune system could also be exacerbated by a new high dose
formulation for those over 65 (Fluzone high dose for seniors). This new
formulation has 4 times the level of vaccine target (60 ug each) and was
approved for use in the US this season. It is unclear if it is currently
being used in Japan in general or the hospital in Akita in particular.
Thus, the clustering of fatal cases may be linked to the vaccinations on
October 29, which limited the immune response to the live H3N2 infection
circulating in the hospital at the time. |
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