The Wisconsin Department of Health Services (DHS) has launched a new data webpage, COVID-19 Illness After Vaccination, which includes a visualization showing the rate of COVID-19 cases, hospitalizations, and deaths per 100,000 among individuals who are fully vaccinated versus individuals who are not fully vaccinated. These data are also presented by month, beginning in February 2021. By displaying the rates side-by-side, users can clearly see the difference in rates between these two groups. The overwhelming majority of Wisconsinites who are infected with COVID-19 are not fully vaccinated.
“The increase in cases we are seeing in Wisconsin right now is being largely driven by the Delta variant, and the overwhelming majority of people who are contracting COVID have not been fully vaccinated. With the original strain of COVID-19, an infected person was likely to infect two other people, who were then likely to infect two additional people for a total of 6 cases from one infection. With the Delta variant, an infected person is likely to infect about five people, who are then likely to infect 25 people for a total of 30 cases from one infection,” said DHS Secretary-designee Karen Timberlake. “The COVID-19 vaccines are still doing their job by stopping the spread of many new infections, and by preventing severe illness, hospitalization, and death.”
In July, people who were not fully vaccinated were nearly 3 times more likely to test positive for COVID-19. Additionally, they were hospitalized for COVID-19-related illnesses at a rate 2.7 times higher than people who are fully vaccinated. People who are fully vaccinated also saw a 10-fold reduction in risk of dying from COVID-19 compared to not fully vaccinated people.
The data clearly show that COVID-19 vaccines are still doing their job by preventing severe illness, hospitalization, and death. However, because no vaccine is 100 percent effective in preventing infection, we do expect some infections among fully vaccinated people. Fully vaccinated people who test positive for COVID-19 more than 2 weeks after their completed vaccine dose series are called breakthrough infections(link is external). The not fully vaccinated population includes all Wisconsin residents with no COVID-19 vaccine doses reported in the Wisconsin Immunization Registry (WIR), an incomplete COVID-19 vaccine series, and those who have not completed the two weeks following vaccination to build full immunity.
DHS has also made two other data updates this week. The COVID-19 cases and deaths by county and census tract, municipality, school district, and zip code have been updated to align with the color scheme used by the Centers for Disease Control and Prevention (CDC) case-rate definitions used to determine level of community transmission on the CDC COVID Data Tracker(link is external). This alignment with CDC’s tracker is important for local decision makers to elect on layering COVID-19 prevention measures within the community based on levels of community transmission and vaccination coverage. DHS has also updated the New confirmed COVID-19 cases by date confirmed, and 7-day average graph to include a date slider. The new function allows users to zoom in on a particular segment of the graph.
The COVID-19 vaccines remain the one of the best ways to protect yourself, your family, and your community from COVID-19 and the highly infectious Delta variant. Unvaccinated people are encouraged get vaccinated as soon as they can and continue following local public health guidance. To find a vaccination location near you visit vaccines.gov(link is external) (https://vacunas.gov/(link is external)) or call 211.
Getting vaccinated, wearing a mask in schools and in public, indoor settings is critical to stopping the spread of the Delta variant. Everyone who has symptoms of COVID-19 or believes they have had exposure to COVID-19 should get tested. Fully vaccinated individuals who have symptoms and are diagnosed with COVID-19 should isolate from others and be clinically evaluated.
For up-to-date information about Wisconsin’s COVID-19 response, visit the DHS COVID-19 webpage.
