The timing of flu is very unpredictable and can vary in different parts of the country and from season to season. Most seasonal flu activity typically occurs between October and May. Flu activity most commonly peaks in the United States between December and February.
People should begin getting vaccinated soon after flu vaccine becomes available, ideally by October, to ensure that as many people as possible are protected before flu season begins. However, as long as flu viruses are circulating in the community, it's not too late to get vaccinated.
Every Day Prevention
In addition to getting a seasonal flu vaccine if you have not already gotten vaccinated, you can take everyday preventive actions such as staying away from sick people and washing your hands to reduce the spread of germs. If you are sick with flu, stay home from work or school to prevent spreading flu to others. More information can be found on the CDC website.