Glossary of Key Terms
Assumption – something that we take as true in a mathematical model, based on current scientific understanding, when exact information or numbers aren’t available. Assumptions can help us find useful results with mathematics when there are some unknowns. For example, in our model we assume that for every person that contracts COVID-19, they will infect, on average, between 1.6 to 3.6 other people.
Benefit-risk ratio – the ratio of the benefits of an action to its risk. For example, if a drug is more likely to cure a certain patient than harm them, the benefit-risk ratio is above 1 – there is more benefit than risk.
Coronaviruses – a group of closely related viruses that usually cause respiratory infections in humans. Sometimes they cause symptoms and sometimes they do not. Symptoms can be mild to severe and can include pneumonia, coma, and death. Common coronaviruses cause mild to moderate illness like the common cold. Other coronaviruses are SARS-CoV (severe acute respiratory syndrome coronavirus), MERS-CoV (Middle East respiratory syndrome coronavirus), and SARS-CoV-2 (the virus causing the current pandemic) and can cause severe illness.
COVID-19 – coronavirus disease 2019, a disease caused by the SARS-CoV-2 virus. Symptoms may include fever and dry cough in milder cases and difficulty breathing in more severe cases.
Epidemic – A sudden increase in the number of disease cases in a particular population.
Herd immunity – As more and more people in a population become immune either through recovery from infection or through vaccination, the chance that a disease can spread decreases. Everyone benefits from extra protection thanks to people who are already immune. When enough people are immune, they act as a shield for vulnerable people, and so the opportunity for the disease to spread becomes so low that we say this population has herd immunity.
Mathematical model – a set of mathematical equations that attempts to simulate a system (for example an epidemic) and so to predict how the system would behave in the real world.
SARS-CoV-2 coronavirus – the name of the virus that causes COVID-19 in humans.
Social distancing – deliberately decreasing contact between people to avoid the spreading of illness.
Vaccination – a person receives parts of a virus or bacterium or weakened versions of the pathogen and develops antibodies against them without getting sick: the immune system now knows how to fight this type of infection. For instance, most children receive Measles, Mumps, and Rubella vaccine (MMR) to prevent them from getting these diseases in the future.