Colorado’s COVID-19 death toll has climbed to its highest levels in a year amid the latest surge in transmission and hospitalizations, and seven-day average deaths have surpassed the average number of deaths expected to be caused by cancer, the state’s leading cause of death.

The state surpassed 8,000 deaths on Oct. 12. It had taken more than three months to move from 7,000 to 8,000, but in the 22 days since the latter threshold was reached, the death toll has climbed to just over 8,600. The state has averaged more than 24 deaths per day since then. 

A Centers for Disease Control and Prevention aggregated projection estimates Colorado will near 9,000 deaths by the end of the month. Even under that pace, the state would’ve reached 1,000 new deaths in less than two months, after a slow summer and spring. Some models listed by the CDC have faster and slower death projections; the agency provides an “ensemble” of these projections.

Based on a Gazette analysis of data from 2015 to 2019, cancer kills an average of 156 Coloradans over a seven-day period. At multiple points in October, the seven-day average of deaths due to COVID-19 topped 200 and, at least twice, 300. 

A spokeswoman for the state Department of Public Health and Environment said in an email that COVID-19 is the fourth-leading cause of death in Colorado this year; the disease has killed 2,548 residents. Cancer has far outstripped it over the balance of the year: More than 6,000 Coloradans have died of that constellation of illnesses in 2021.

The spokeswoman said the department does “not have estimates of cause of death rankings for the most recent few months.” 

In the eight weeks between Sept. 4 and the end of October, the state has reported more than 100 COVID-19 deaths seven times. The last time that had happened once was in January, when the state was recovering from its late 2020 surge. Recent deaths are still far eclipsed by that wave, when more than 400 residents died in three successive weeks. 

State officials said earlier this week that deaths since the current fifth wave began have been overwhelmingly among the unvaccinated. Gov. Jared Polis said there had been roughly 300 deaths among the oldest Coloradans. Two hundred of those were among the unvaccinated, which account for as little as 5% of that total age group. The remaining 93% to 95% who are inoculated contributed roughly 100 deaths. The numbers are much starker for younger populations.

Rachel Herlihy, the state’s epidemiologist, told reporters this week that the vaccine is 100% effective in preventing death for people under the age of 39; nearly 95% effective for those between the ages of 40 and 59; 93.8% effective for the 60 to 79 band; and 77.6% effective for those over the age of 80.

Those numbers, particularly for the older residents, will improve when boosters begin to flow more readily. Though exact explanations remain elusive, officials and public health experts have suggested one explanation for the recent surge in cases and hospitalizations is waning immunity: Some of the state’s most vulnerable residents were inoculated first, in January, and thus have had the longest amount of time for which their immunity to decline.

The boosters, however, indicate significant success in preventing both hospitalization and death.

Gazette staff writer Evan Wyloge contributed to this report.