In Dane County, breakthrough infections rise but unvaccinated COVID-19 cases and hospitalizations far higher

Us Health Virus Vaccines
Vials and syringes of the Johnson and Johnson Janssen Covid-19 vaccine are displayed for a photograph at a Culver City Fire Department vaccination clinic on August 5, 2021, in California. (Photo by Patrick T. FALLON / AFP) (Photo by PATRICK T. FALLON/AFP via Getty Images)
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MADISON, Wis. — While breakthrough cases among vaccinated individuals are rising in Dane County due to the Delta variant, just-released data from Public Health Madison Dane County shows the hospitalization rate for vaccinated individuals remains far below those who are unvaccinated.

Since July 1, the Delta variant of the coronavirus has been the dominant version of the virus in Dane County, with infections and hospitalizations rising as a result. Before that, only .02% of fully vaccinated people were being diagnosed with COVID-19 between January and June; now, infections have risen somewhat. However, COVID-19 infections are 2.5x as high among the unvaccinated, and more than twice as likely to be hospitalized as a result.

Breakthrough infections in Dane County

Breakthrough infections have been more common since the rise of the Delta variant, but hospitalizations and deaths remain much lower than in the unvaccinated. 25 people were hospitalized and 3 died in Dane County from January through August who were fully vaccinated; that’s less than .01% of the vaccinated population of more than 371,000.

According to PHMDC, most of those hospitalized among the breakout infections had other comorbidities or were first hospitalized for a different reason before COVID-19 extended their stay; the median age was 74.

Unvaccinated infections in Dane County

Infections among unvaccinated people hits those over 65 the hardest, according to PHMDC data. In July, unvaccinated people 65 or older were 6.1 times more likely to test positive for the virus, and almost 10 times more likely to be hospitalized when compared to their 65 and older vaccinated peers.

For those under 65, the chances of testing positive were 1.9 times as likely than their vaccinated peers, and 4.6 times more likely to be hospitalized.

Emerging concerns

PHMDC plans to monitor a few different warning signs, they noted, as the Delta surge continues.

Specifically, they’re watching for an increase in hospitalizations, although that may not indicate an increase in infections among Dane County residents, given the large regional health care hub in Madison.

An increase in children getting sick is another issue PHDMC is watching for at a local and national level. “There isn’t strong evidence that the Delta variant is more severe for younger people, but since children under 12 can’t be vaccinated yet, they remain vulnerable to infection, particularly when community levels of COVID are high,” a PHMDC blogpost said.

Finally, any new emerging variants would be a cause for concern, given the nature of viruses to continue mutating. So far, PHMDC noted, there’s been no new variant identified that can fully evade existing vaccines.