Federal officials plan to double the stockpile of emergency bird flu vaccines as they identify more people infected with the disease. Three manufacturers were awarded $72 million to increase pandemic preparedness including against avian influenza, officials announced in a Friday morning briefing.

The two workers had mild symptoms, including eye redness, according to the California Department of Public Health. This symptom has been seen among other livestock workers infected with bird flu in the U.S. The two workers showed no respiratory problems, the state health agency said in an update. Neither were hospitalized.