DENVER (AP) -- Colorado is having its worst whooping cough season in at least six decades.

The state health department said Tuesday that 1,407 cases were reported as of Dec. 8. That's the highest number on record since 1948, when there were 1,833 cases.

One person from Larimer County died of whooping cough in October. That's the first death from whooping cough, officially known as pertussis, in Colorado since 2005, when two infants died.

The health department recommends that all adults and children receive the whooping cough booster vaccine in addition to getting a flu shot this year.

The vaccine now in use doesn't last as long as previous vaccines and officials think that may be one reason for the increase in cases in Colorado and across the country.