While influenza cases can happen any time of the year, the flu season officially started Sunday. In Colorado, 60 cases have been confirmed since June.
According to the Centers for Disease Control, the most active months for flu cases happen between December and February. The CDC tracks weekly cases of flu across the U.S. and reports ‘low’ activity as of the most recent data from the week of September 21.
The makeup of flu vaccines changes each year to target specific viruses. In 2020, the CDC says flu vaccines will guard against up to four viruses that 'research suggests will be the most common.' Three-component vaccines should contain the following in the 2019-2020 season, according to the CDC:
- A/Brisbane/02/2018 (H1N1)pdm09-like virus (updated)
- A/Kansas/14/2017 (H3N2)-like virus (updated)
- B/Colorado/06/2017-like (Victoria lineage) virus
The CDC recommends people 6 months and older receive a yearly influenza vaccination. People in high-risk groups are potentially more susceptible to dangerous flu-related complications that can lead to hospitalization and death.
Adults 65 years and older, pregnant women, young children, people with asthma, diabetes, HIV/AIDS or cancer are considered people in high-risk groups. People with an allergy to eggs or ingredients in the vaccine should talk to their doctor before getting the flu shot, according to the CDC.
- Questions about the flu shot? Read more about who should or should not get the vaccine.
In Colorado, there were 3,832 people hospitalized due to influenza in the 2018-2019 flu season. The Colorado Department of Public Health and Environment reported the most active period in last year’s flu season was at the end of December and the beginning of March, in terms of hospitalizations.
The majority of hospitalizations in Colorado were in the 65 and above age group. 3 children in Colorado died from flu-related illness in last year's season.
- Find a flu vaccine location in Colorado: Click to view locations on a map.
Influenza is a respiratory illness that is highly contagious. Symptoms include high fever, headache, tiredness, dry cough, sore throat and muscle aches. Health complications from influenza include bacterial pneumonia and dehydration, according to Boulder County.