1. Jenner E: An inquiry into the causes and effects of the Variolae vaccinae, a disease discovered in some of the western countries of England, particularly Gloucestershire, and known by the name of “The Cow Pox”. Reprinted by Milan: R Lier & Co, 1923:84 1798.
2. Darton TC, Blohmke CJ, Moorthy VS, Altmann DM, Hayden FG, Clutterbuck EA, Levine MM, Hill AV, Pollard AJ. Design, recruitment, and microbiological considerations in human challenge studies. Lancet Infect Dis. 2015;15:840–51.
3. Good clinical practice guide. 3rd ed. London: The Stationary Office; 2014.
4. The Rules Governing Medicinal Products in the European Union, Guidance on INPS and NIMPs 1 Eudralex 10.
5. Regulation (EU) No 536/2014 of the European Parliament and of the Council of 16 April 2014 on clinical trials on medicinal products for human use, and repealing Directive 2001/20/EC Text with EEA relevance. (Union E ed., vol. 536/2014 Brussels: Official Journal of the European Union; 2014.