For example, when cross-reactivity of 40% has been observed and 15% are vaccinated the mean risk of infection would be 14%, 11.5% and 5.6% for RVP, AIP and PIP, respectively; whereas when 30% are vaccinated the mean risk would be 8.6%, 4.6%, and 3.6% for RVP, AIP and PIP, respectively. This evidence concerns the gene AIP and infection.