Newschannel 6 spoke with Christy Mays, Registered Nurse with the Wichita Falls/Wichita County Public Health District Thursday evening.
She answered questions regarding the flu vaccine that may not protect against a strain of the virus circulating the country.
The Centers for Disease Control and Prevention is alerting doctors about a flu virus strain not in this year's flu vaccine.
About half of the samples tested this season are a new H3N2 strain which tends to cause more severe disease, especially in very young children and the elderly.
Pregnant women and people with chronic conditions such as asthma and heart disease are also at high risk.