FOX31 Denver

Vaccines appear effective against delta variant

DENVER (KDVR) — We might not know too much about the delta variant’s impact on hospitalization or death, but evidence in Colorado does point to vaccines’ effect on keeping it tamped down.

The so-called delta variant, first identified in India and now active in the United States, has caused a new stir among health officials. Colorado’s health department estimates over 70% of the state’s new COVID cases are of the delta variant. The Centennial State is one of the state’s with the highest proportion of the delta variant, according to U.S. Centers for Disease Control and Prevention data.

So far, none are predicting another massive wave of cases and deaths like the one in late fall and winter 2020. Early data is spotty on whether the delta variant causes more hospitalizations or deaths.

Data is slightly clearer about vaccines – specifically that vaccines are effective against the delta strain.

Those with only one dose of the vaccine are slightly less protected against the delta variant than the wild COVID strain, leaving about 277,000 partially vaccinated Coloradans with reduced immunity. The estimated effectiveness of full vaccination is still comparable to effectiveness against other strains, however.

One thing is clear. There is a definite connection between the delta variant dominance and Colorado’s COVID stats.

Colorado’s recent COVID stats are far from a large-scale wave, but they do suggest the state is seeing greater viral transmission than a few weeks ago when the delta variant wasn’t as widespread.

Of the main measurements used to chart COVID progress, only deaths among cases is going down. The number that aren’t going down, however, track upward with the delta variant’s presence.

The average new daily cases, new hospital intakes and average test positivity have each either stalled or have rolled gently upward since July 20, when the state tracked the largest portion of delta variant presence. In the week ending that day, 83% of the state’s new cases were delta type.

County vaccination totals confirm that vaccines do their part to keep heavy delta variant zones from having higher number.

The map above shows Colorado county’s by their vaccination rate. The lighter-colored counties have lower rates, the darker have higher rates.

Denver metro counties and High Rockies counties tend to have higher rates, while eastern plains and Western Slope counties have lower rates.

A map of Colorado counties by their most recent COVID rate per 100,000 shows almost exactly the opposite.

The counties with the highest case rates – including Western Slope counties and a several eastern plains counties – tend to be the counties with the lowest rates of vaccination.

Naturally, these data are still messy. But they do confirm what state officials say: the more vaccinations take place, the lower a population’s chances of COVID spread through the delta variant.