measurement datum vaccine effectiveness rate Oliver He data item Melanie Courtot Hadler TC, et al. Immunization in developing countries. In: Vaccines. Editors: Plotkin S, et al. 2008. p1542-71. WEB: http://en.wikipedia.org/wiki/Influenza_vaccine A measurement datum that measues the vaccine effectiveness. It is assessed with respect to prevention of the disease against which the vaccine is given. One simple method to estimate vaccine effectiveness is to use routine data on notifications of disease cases in vaccinated and unvaccinatted children and to compare the porportion of cases vaccinated with the vaccine covervage among the same age group in the general population. If p is the proportion vaccinated in the population and c is the proportion of cases reported to be vaccinated, then VE = (p-c)/p(1-c) x 100%.