MADISON, Wis. - The Wisconsin Department of Health Services (DHS) on Thursday, April 8 released a new data table on its variant webpage that shows SARS-CoV-2 variant proportions by Health Care Emergency Readiness Coalition (HERC) region.
The variants page now also includes information on two additional variant strains of SARS-CoV-2: variants B.1.427 and B.1.429.
The DHS first identified these variants in Wisconsin in December 2020, and is now tracking them and displaying them publicly following the CDC's recent classification update on March 17, 2021.
These strains were recently upgraded from variants of interest to variants of concern. SARS-CoV-2 variants are common as viruses change constantly through mutation.
"With new variants spreading in Wisconsin, we are updating our variant data page to include more detail about where these variants are being detected," said DHS Deputy Secretary Julie Willems Van Dijk. "Because these new variants of concern spread more easily than the original strain of SARS-CoV-2, it is important to get vaccinated when you are able. Vaccines, along with our other public health practices, give the virus less of an opportunity to spread and mutate."
Improvements to the variant webpage provide information on variants circulating in the different regions of the state. The new variant data tables show the proportion of sequenced specimens that are attributed to each variant of concern. This provides a better perspective on how common each variant of concern is regionally.
The newest variants of concern -- referred to as B.1.427 and B.1.429 -- were first discovered to be circulating in California in samples dating back to May 2020. Variants B.1.427 and B.1.429 share many attributes, with the only significant difference found in their spike protein mutations.
According to epidemiologic and modeling studies, researchers have found that both variants spread more rapidly and easily than the original strain of SARS-CoV-2. However, these variants have shown to be less transmissible than variant strains B.1.1.7 and B.1.351 -- otherwise known at the U.K. and South Africa strains.
To date, 216 cases of B.1.427 and B.1.429 have been confirmed in Wisconsin since December 2020.
Variants are identified through a process called whole genome sequencing. Whole genome sequencing takes a sample of the virus from a positive SARS-CoV-2 test specimen and reads its genetic code. The DHS, the Wisconsin State Laboratory of Hygiene, and other laboratory partners regularly perform whole genome sequencing on a portion of positive tests.