The nasal mist form of the influenza vaccine at Kaiser Park Shadelands in Walnut Creek, Calif., on Friday, Oct. 11, 2013. (Dan Rosenstrauch/Bay Area News
The nasal mist form of the influenza vaccine at Kaiser Park Shadelands in Walnut Creek, Calif., on Friday, Oct. 11, 2013. (Dan Rosenstrauch/Bay Area News Group) ( DAN ROSENSTRAUCH )