There has been considerable debate as to whether the early policy of the Government was one of seeking to achieve so-called “herd-immunity”. The US Centres for Disease Control and Prevention defines community immunity/herd immunity as: A situation in which a sufficient proportion of a population is immune to an infectious disease (through vaccination and/or prior illness) to make its spread from person to person unlikely. Even individuals not vaccinated (such as newborns and those with chronic illnesses) are offered some protection because the disease has little opportunity to spread within the community. Also known as herd immunity.102