An infectious disease expert says the relatively mild cases of avian influenza detected so far among dairy workers don’t warrant making a vaccine available to them, even as they work to contain and prevent spread of the contagious virus among herds.Dr. Shira Doron, an epidemiologist and chief infection control officer for Tufts Medicine in Boston, said the minor spread of the H5N1 among humans – and no reported instances of humanto- human transmission – makes any widespread administration of a vaccine premature right now.“There are also many logistical issues that would be associated with deployment of vaccine to farm workers – language barrier, undocumented status, compliance – so that is not the plan at this time, “ Doron said Friday morning during an Infectious Diseases Society of America teleconference.H5N1 has circulated globally for decades, she said. Analysis of the strains currently circulating shows them to be poorly suited for transmission between humans and with low pandemic potential, according to Doron.Human patients have also responded well to antiviral treatments such as Tamiflu, the doctor said.The current avian flu strains have led to two severe cases in humans. One involved a 65-yearold person from Louisiana who contracted the virus from exposure to a combination of a noncommercial backyard flock and wild birds, state health officials said. It was the nation’s first ever fatal human case of avian flu, though the patient was reported to have underlying conditions that worsened after they contracted H5N1. The other severe case was a teen in Canada who had to be admitted to a hospital’s intensive care unit. That patient contracted the virus from wild birds, Doron said.Dr. Julio Figeroua, LSU Health chief of infectious diseases and a professor at Louisiana State University’s medical school in New Orleans, also took part in the IDSA teleconference. There have been no secondary avian flu cases related to the patient in Louisiana who died, he said.“We have people who do hunting, hunting of geese and ducks, and so advisories have been put out to those for proper handling of those particular animals,” Figeroua said. “A lot of backyard flocks that are here and in urban and suburban areas are potentially also potential sources for transmission.”In addition to 919 dairy herds in 16 states, the highly pathogenic H5N1 strain of bird flu has impacted more than 133 million poultry farms in all 50 states as of Wednesday, according to the U.S.