Figure 2From: Intradermal influenza vaccination of healthy adults using a new microinjection system: a 3-year randomised controlled safety and immunogenicity trial Study flow chart. ID, intradermal; IM, intramuscular; N, number of subjects. *As one of the study centres (the Czech centre) did not participate in the third part of the study, a large number of subjects were discontinued from the study between the second and third vaccinations.Back to article page