illness
immunise, immunity, inoculate, vaccinate
immunise: to deliberately administer an antigen to an individual in such a way that the individual develops an adaptive immune response to the antigen
immune: the state of being able to mount an adaptive immune response against an antigen that the individual has been exposed to before. An individual can become immune through immunisation or as a result of natural infection. Immunity can wane over time, so an individual may no longer be immune if they have been immunised in the past
inoculate: means the same as vaccinate and has been largely replaced by vaccinate when referring to human immunisation; still used in cell culture (for introducing cells into a new culture medium) and in animal research (for introducing a microorganism into a laboratory animal)
vaccinate: to administer antigenic material (a vaccine) to stimulate an individual’s immune response. The aim of vaccination is for the individual to be immunised (ie to become immune); however, an individual can be vaccinated but not become immune (e.g. as a result of vaccine failure)
immunity
impact, effect
impact (noun): a marked effect or influence
In risk analysis, impact is used to describe the size of an effect associated with a risk event. High-impact events are more serious than low-impact events.
impact (verb): to have a noticeable effect on
The use of impact as a verb has only recently become acceptable. It should not be overused and should be restricted to events that have large, significant or serious effects. Consider using affect or influence instead:
See also affect, effect
improve
in vitro, in vivo
in vitro: in an artificial environment (Latin for in glass)
in vivo: in a living organism
in vivo
incidence, prevalence
incidence: the number of new cases (e.g. of disease) occurring in a population of stated size during a stated period of time
prevalence: the number of cases (e.g. of disease) existing in a population of stated size at a particular time
increase
inflammable
inhibit
Inhibit can mean either ‘stop’ or ‘slow down’; care is therefore needed to avoid ambiguity.
inoculate
interval, period
interval: a length of time between 2 specified points
period: a specified portion of time
isolation, quarantine
isolation: the separation of a person (or animal) who is ill from healthy people (or animals), to prevent the spread of disease
quarantine: the separation from other people (or animals) of a person (or animal) who has potentially been exposed to a communicable disease, to prevent the spread of disease. Importantly, the individual in quarantine does not yet have any signs or symptoms of the disease – that is, they are not currently ill with that disease. The word quarantine relates to the Italian word for forty – during the Black Plague in 14th-century Europe; ships were required to wait for 40 days before their passengers could come ashore. The period of quarantine differs for different diseases. Quarantine can also be applied to plants or objects such as vehicles