Table 1 VE (vaccine efficacy) methods, interpretation, and formulas

VE_RR

Vaccine-induced proportion reduction in probability of infection during follow-up

\({\mathrm{VE}}_{\mathrm{RR}}= 1-\mathrm{RR}= 1-\frac{{\mathrm{p}}_{\mathrm{v}}}{{\mathrm{p}}_{\mathrm{c}}}\)

VE_HR

Vaccine-induced proportion reduction in hazard of first infection during follow-up

\({\mathrm{VE}}_{\mathrm{HR}}=\) 1 – HR

VE_molFOI

Vaccine-induced proportion reduction in molecular force of infection (molFOI)

VE_molFOI = \(1- \frac{\mathrm{molFOI\, of\, vaccinees}}{\mathrm{molFOI\, of\, controls}}\)

VE_C

Vaccine-induced proportion reduction in mean number of clones per exposure that develop into a blood stage infection

\({\mathrm{VE}}_{C}= 1-\frac{{\overline{x} }_{v}}{{\overline{x} }_{c}}\mathrm{HR}\)