Police tape blocks off Wuhan&x27;s Huanan market, linked to several of China&x27;s first coronavirus patients. Scientists are trying hard to determine how Covid-19 started, where it came from and how. An additional COVID-19 winter booster is strongly recommended for people aged 50 and over, and other people at higher risk of serious illness from COVID-19, such as. older people; people living in aged care; people living in disability care; Aboriginal, Torres Strait Islander and Pacific Islander peoples, after discussion with their doctor or clinician. Case activity This section provides an overview of counties in Wisconsin based on COVID-19 case activity levels.Case activity is a metric that combines case burden (rate per 100,000 people) and trajectory (percent case change). Confirmed case activity is an important starting metric to understand current COVID-19 levels in your community. Wear a mask indoors in public. Stay up to date with COVID-19 vaccines. Get tested if you have symptoms. Additional precautions may be needed for people at high risk for severe illness. People may choose to mask at any time. People with symptoms, a positive test, or exposure to someone with COVID-19 should wear a mask. COVID-19, which is caused by the SARS-CoV-2 virus, can cause mild to severe symptoms or even death in patients. The illness, which spreads mainly though close contact with an infected person.