COVID-19 Glossary

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An infection that causes the brain to inflame. It can be extremely dangerous and fatal. Coronaviruses are known to infect the brain, spine and nervous system in lab animals. One case of viral encephalitis was linked to COVID-19, but it is not a major concern with the virus.


An enzyme is a molecule made up of different proteins. They’re molecules that our bodies use to do things. The enzyme myosin makes muscles contract, and the enzyme insulin tells our blood when to absorb sugar. Viruses use enzymes to hijack our cells and make copies of themselves. Many antiviral treatments work by targeting enzymes: to fight a viral infection, you take away the tools a virus needs to make more of itself.


A large outbreak of disease, taking place over a short period of time. An epidemic might infect a region or a country. Epidemics usually happen when a new disease emerges or when something happens to make people less immune to a disease. A pandemic is an epidemic that spreads to multiple large regions, like several continents or countries. 


The study of how infectious diseases spread, occur, and are controlled. John Snow (not to be confused with the character Jon Snow of “Game of Thrones” fame) is considered the founder of modern epidemiology. He famously traced a 19th-century cholera epidemic to a contaminated water pump and the pump handle. He chlorinated the water and removed the pump handle, and the disease ended. Today, sometimes epidemiologists talk about tracing modern diseases back to the metaphorical “Pump Handle.” 

essential activities

Tasks essential to maintain health and safety, such as obtaining medicine or seeing a doctor.

essential government functions

All services needed to ensure the continuing operation of the government agencies and provide for the health, safety and welfare of the public.


flatten the curve

Flattening the curve refers to taking protective actions, often called community mitigation measures, that help slow the spread of a disease so the health care system does not get overwhelmed by having a lot of very sick people all at once. The protective actions can be things like canceling large gatherings, keeping space between people (called social distancing), and continuing to do things like washing hands, covering coughs, and staying home when sick.


Fomite is an object (such as a dish or a doorknob) that may be contaminated with infectious organisms and serve in their transmission.” While this word is infrequently encountered, there has been considerable talk of late about possible surfaces and objects which might harbor infectious substances, and it may well be useful to have this specific word at hand.



An online database of genetic sequences from around the world and maintained by the national library of medicine.



Those considered high-risk include older people or those with certain underlying health conditions. These include blood disorders, chronic kidney disease, chronic liver disease, a compromised immune system, late term or recent pregnancy, endocrine disorders, metabolic disorders, heart disease, lung disease, and neurological conditions.

home isolation

Persons with COVID-19 who have symptoms or laboratory-confirmed COVID-19 who have been directed to stay at home until they are recovered. (Source:



An immune system that isn’t functioning correctly. A person can be immunocompromised by diseases like AIDS or taking some anti-cancer drugs, but also by losing sleep, not drinking enough water and eating poorly. Pregnant women aren’t considered immunocompromised, but changes to their immune system can make them more susceptible to some diseases.


People with immune systems that are (usually artificially) weakened. People with organ transplants take immunosuppressants to stop their immune systems from attacking the organs. Immunosuppressed people are also immunocompromised.

in vitro

A lab test done on cells, not living things. We do in vitro tests on drugs, diseases and chemicals to see how they impact human cells.

in vivo

A lab test on a living organism, whether that’s a plant or an animal or something else. Drugs are usually tested in vivo to make sure they’re safe and that they work.

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