The spread of influenza in Colorado is far below what it has been in previous years, officials said, thanks to mitigation efforts undertaken to prevent the spread of COVID-19 and the state's push to vaccinate more people this fall.

In recent years, Denver has had as many as 200 total flu hospitalizations by the end of December.

The average number of hospitalizations between 2015 and 2019 is nearly 114.

For the 2020-21 flu season, which began in October and will stretch into the spring, there has been just one flu hospitalization over the first three months.

There have also been zero flu outbreaks in Denver, zero outbreaks statewide in long-term care facilities and just 14 flu hospitalizations for all of Colorado.

According to state data, in the past week, 18 hospitals monitored by the state tested more than 2,800 specimens for flu. Only three were positive. 

"Moral of the story -- influenza activity (both hospitalization flu and overall flu) is down a tremendous amount in 2020 compared to the last few years," an epidemiologist with Denver Public Health said in an email.

"This is likely due to a multitude of factors, but mainly due to vaccine campaigns in early fall as well as prevention methods in place from COVID."

According to a spokeswoman for the state Department of Public Health and Environment, the number of people who received a flu shot this year was up more than 17%.

In the three-county area covered by the Tri-County Health Department, it was a 25% increase, said Lynn Trefren, the agency's influenza liaison.

Colorado isn't alone in seeing a remarkably mild flu season.

Data from the Centers for Disease Control and Prevention indicate low levels across the country.

As the state ramped up its flu vaccine distribution in October, experts said the Southern Hemisphere had a slow season thanks to the COVID shutdowns that were widespread in the spring. 

The apparent success of the flu vaccine push might be a positive sign for state health officials as they ramp up distribution and administration of the COVID  vaccine.

Officials said earlier this year that they were treating flu vaccine as a dry run for its COVID counterpart.