Because of the problems with growing the flu strain needed to make the vaccine it put manufacturers behind schedule. But the Centers for Disease Control issued a report saying that while supplies may run a little late, there's plenty to go around for the oncoming flu season. Taking the vaccine late should keep most people safe from the flu. Most flu cases peaked between January and March. Officials say that immunizing most people by December should provide protection by the traditional peak season.
Any age group does.
The flu can lead to complications, such as pneumonia. This is more common in people over 65 years of age, anyone with other health problems and very young children. Approximately 100,000 people per year are hospitalized for flu-related illness. It is highly recommended by public health officials for the high-risk individuals to get vaccinated first. Although flu viruses are common, they can be deadly to some.