Wear a Mask

Without a mask, respiratory droplets easily travel 12 feet, and in some cases, up to 26 feet. Many people are infected with the virus, but do not develop the disease. Infected people without symptoms are nearly as infectious as symptomatic individuals, so universal mask wearing is essential to preventing disease spread. With a mask, it is moderately safe to spend short periods of time as close as 6 feet from other people who are also wearing masks. In viral hotspots, people living with high-risk household members may need to wear a mask at home.


Masks are recommended worldwide, and required in California schools and most public places. 


Routine Medical Care


Annual flu vaccination rates 





Wash Hands


Coronavirus can stay active on the skin for 9 hours, and up to 28 days on hard surfaces. Soap and water can grab onto the virus, damage it, and wash it away. Hand sanitizers containing at least 60% alcohol deactivate the virus, so it can't get you sick. Whether using soap or sanitizer, scrub a minimum 20 seconds. Watch the Centers for Disease Control explain how to wash your hands to remove the most virus. 




Schools closed around the world. 


See Sacramento County guidelines for schools





Outdoors outdoor air disperses respiratory droplets more quickly than indoor air. 


Indoor air requires ventilation to bring in as much outdoor air as possible. Natural ventilation uses open doors and windows to bring in fresh air. Weather, outdoor allergens or air qualilty limit the times when natural ventilation can be used.  


Whole building mechanical ventilation systems move indoor air out, and filter outdoor air to bring it inside. MERV 13 filters 


Disease Surveillance


It is common for viruses to jump from animals to humans (zoonotic diseases). Three new strains of coronavirus have emerged in recent decades. The pathogen that causes covid-19 is thought to originate in animals, and SARS and MERS have already been traced to an animal source. An estimated 800,000 viruses currently circulating in animals are capable of transferring to humans. The better scientists can monitor these diseases, the better prepared we will be when the next one makes the jump. 



What's a Coronavirus?


Coronavirus describes the crown-like spikes seen on several virus strains. They can affect people, bats, rats, other mammals, and some (like the new Coronavirus) affect multiple species. There are several strains of coronavirus that frequently cause mild acute respiratory system illness in humans, like a common cold. In recent years, severe SARS and MERS coronavirus strains emerged. SARS emerged in 2003 and was eradicated by 2004. MERS emerged in 2012, and was contained, but continues to cause some new infections


In December 2019, another new coronavirus pathogen (SARS-Cov-2) was identified from a new illness outbreak in China. The disease became known as COVID-19 (coronavirus disease, 2019). It spread rapidly, and quickly became the "most severe health emergency" of our lifetime. 


Most infections are caused by close contact with infected people. "The virus can spread from an infected person’s mouth or nose in small liquid particles when they cough, sneeze, speak, sing or breathe heavily." Some infections result from aerosol droplets, which may stay in the air up to 3 hours. Less often, infections result from touching a surface with the virus, and rarely, infections result from contact with infected animals.


The virus enters the body from the lining of the eyes, nose, and mouth, then destroys cells and uses them to create more virus. An estimated 40% of infected people never have symptoms. Many people develop a mild illness. Some people develop severe illness, and around 3% of infections lead to death. 


Recovery can be a long process, and many long term impacts are not known. Coronavirus can scar the lungs, create long-term damage to the heart, and cause blood clots, brain and kidney damage.  


Several actions can help to avoid illness and limit the spread of the virus. 

Safety Protocols

Related Research Guides

Preventing future Pandemics



Who is vulnerable to infection?

Other Impacts





Incarcerated populations 





Domestic Violence


As some of us shelter in place, others are confined with violence. A sharp rise in domestic violence during lockdowns has been called a "shadow pandemic." 







A record number of early votes were cast





Food Security