Two outbreaks of mumps in children vaccinated with the Rubini strain in Spain indicate low vaccine efficacy Pons, C and Pelayo, T and Pachon, I and Galmes, A and González, L and Sánchez, C and Martinez, F, Eurosurveillance, 5, 14 (2000), https://doi.org/10.2807/esm.05.07.00014-en