The Colorado Department of Public Health and Environment (CDPHE) and the Colorado School of Public Health released the most recent statewide modeling report showing the state’s SARS-CoV-2 epidemic is declining. The effective reproduction number for SARS-CoV-2 statewide is below one at 0.77, indicating that SARS-CoV-2 infections are still occurring but at a decreasing transmission rate. Currently, 1 in 390 Coloradans are estimated to be infected.
There are large differences in estimated immunity and in vaccination uptake across the state. Regions of the state with higher vaccination rates have fewer SARS-CoV-2 cases, hospitalizations, and deaths. There are large differences in vaccine uptake around the state. The modeling team anticipates that regions of Colorado with low vaccination rates at present will be areas of concern in the months ahead.
Based on the recent increase in the Delta variant in the state, the modeling team estimates that approximately 90% of cases could be due to the highly infectious variant strain. The more transmissible Delta variant poses the greatest risk to unvaccinated Coloradans.
The modeling report estimates that 52% of the total population of Colorado is immune. The percentage of the entire population that is vaccinated includes both those eligible and those not eligible (right now, children under 12 years of age are not eligible to be vaccinated). This estimate accounts for estimated prior infections, vaccine doses, and vaccine efficacy. The percent of people vaccinated used in the modeling report includes anyone who has received at least one dose of vaccine through June 27. In order to determine immunity levels from vaccination alone, those doses are weighted on overall vaccine efficacy and whether the fullest immunity possible has been achieved based on time elapsed since vaccination. As of the morning of July 6, 70.25% of Colordans 18+ have received one or more doses of the COVID-19 vaccine.
The latest modeling provides projections based on COVID-19 hospital census data through June 28 and vaccination data through June 27, 2021.
The Colorado School of Public Health (ColoradoSPH) assembled the expert group that works with the state on modeling projections. The group includes modeling scientists at the ColoradoSPH and the University of Colorado School of Medicine at the CU Anschutz Medical Campus, as well as experts from the University of Colorado Boulder, University of Colorado Denver, and Colorado State University. The models are based on Colorado data and incorporate assumptions reflecting the current state of the science.
All previous modeling reports are available on the Colorado School of Public Health’s COVID-19 website.
Continue to stay up to date by visiting covid19.colorado.gov.