Glossary
| Term | Definition |
|---|---|
| Variance | A measure of how different the numbers in a set are from one another. For example, the two sets of numbers {6, 2, 3, 1} and {2, 4, 3, 3} have the same average (or mean) of 3, but the first set has a greater variance. Science General |
| Variolation | The historical practice of deliberately infecting people with material from smallpox sores to induce immunity. It preceded Edward Jenner's safer cowpox vaccination. Vaccines |
| Vector encoding | A vector encoding (often called an embedding) is a dense list of numbers that an AI model produces to capture the meaning or visual characteristics of an item—the end goal is that similar items will end up with nearby numbers in the same space. Artificial Intelligence |
| Viral Vector Vaccine | A vaccine that uses a modified, harmless fraction of a different virus (a vector virus) associated with an antigen that can induce production of important instructions that are delivered to the body's cells. Vaccines |
| Virulence | The relative capacity of a pathogen to overcome body defenses and elicit symptoms. Vaccines |
| Virus | A tiny organism that multiplies within cells and causes diseases such as chickenpox, measles, mumps, rubella, and hepatitis. Viruses are not affected by antibiotics, the drugs used to kill bacteria. Vaccines |
| Waning Immunity | The gradual decline of protection after vaccination or infection. A fall in antibody levels does not necessarily mean an equal loss of protection. Vaccines |
| Water Fluoridation | Adjusting fluoride in public water supplies to a level that reduces tooth decay. A frequent target of misinformation about safety. Public Health |
| Water Vapor | The most abundant greenhouse gas, it is the water present in the atmosphere in gaseous form. Water vapor is an important part of the natural greenhouse effect. While humans are not significantly increasing its concentration through direct emissions, it contributes to the enhanced greenhouse effect because the warming influence of greenhouse gases leads to a positive water vapor feedback. Climate Change Denial |
| Weather | Weather is the day-to-day, short-term state of the atmosphere at a specific time and place, defined by variables like temperature, humidity, precipitation, wind, and atmospheric pressure. Climate Change Denial |