Alabama reports one more low-path H7N9 avian flu outbreak
Animal health officials in Alabama yesterday reported one more low-pathogenic H7N9 avian influenza outbreak, this time affecting a commercial farm in Cullman County, located in the north central part of the state, not far from where earlier events occurred.
The Alabama Department of Agriculture and Industries (ADAI) has now reported six low-path H7N9 outbreaks. The others are the original three events in Madison, Lauderdale, and Jackson counties and additional detections reported on Mar 21 in Madison and Pickens counties.
Two other southeastern states—Tennessee and Kentucky—have also reported recent low-path H7N9 outbreaks. Tennessee officials had also reported a pair of highly pathogenic H7N9 outbreaks. The H7N9 viruses recently detected in the United States are related to North American wild bird lineages and have no connection to the H7N9 strain sickening people and poultry in China.
Mar 23 ADAI list of low-pathogenic avian influenza outbreaks
Study shows 3-strain flu vaccine yields better immune response in lab
A trivalent (three-strain) version of a flu vaccine more fully activated dendritic cells—key first-response immune cells—than did its monovalent (one-strain) counterpart, perhaps indicating why some vaccines underperform even when their strains are well matched to circulating flu strains, according to a study in Science Translational Medicine yesterday.
A team of US researchers conducted a cell-culture study to determine why Sanofi's unadjuvanted monovalent pandemic Fluzone vaccine (MIV) was 35% less effective at preventing influenza than was Fluzone TIV, the trivalent seasonal flu version.
The investigators discovered that both vaccines could activate plasmacytoid dendritic cells, but only TIV induced antiviral responses in other types of dendritic cells. In addition, they found that people who received MIV did not show early interferon (immune-boosting) responses in the blood, but those who received TIV did.
The results might help explain vaccine underperformance that is not caused by antigenic mismatch, according to a summary of the study published with its abstract.
Mar 22 Sci Transl Med study