The reports include an outbreak at a large Alabama gamebird farm.
In influenza news, US flu cases appear to be rising, and officials have confirmed more avian flu outbreaks in US poultry.
The birds had recently migrated from Argentina, where the virus has spread over the past few months.
Minnesota and South Dakota reported more outbreaks at commercial turkey farms.
In another development, officials announced early results of vaccination in endangered California condors.
The small rise in poultry outbreaks began earlier this month, following continued circulation in wild birds over the summer.
The older clade, known to circulate in Cambodia's poultry, was also identified in cases the country reported earlier this year.
The study provides proof of concept of a new tool for curbing outbreaks that avoids thorny issues with vaccination.
It's not clear if the virus is an older clade that infected two people earlier this year or the more recent clade circulating globally.
Over a 4-month period, protection with the Novavax vaccine was stable against symptomatic COVID infection.