Retirement communities, dormitories, nursing homes, rehabilitation facilities, psychiatric wards, and prisons are High-Risk Institutions for diseases transmission. COVID-19 is a rapidly transmitting disease requiring hospitalization in about 20% of cases, ICU care in 10%, and resulting in death in 2-4%. Complications rapidly increase for persons 50 years old and above with comorbidities such as heart failure and coronary artery disease further increasing risk. COVID-19 can transmit even with mild symptoms (coughing, sneezing or elevated temperature) and perhaps before symptoms appear. Reducing the likelihood of transmission is imperative in high-risk institutional environments as found in China's Rencheng Prison and South Korea's Cheongdo Daenam hospital. Here are guidelines for prevention by introducing barriers to transmission from outside.