In the wake of the measles outbreaks, which occurred in England in 1992, and on the basis of analyses of seroepidemiological data combined with mathematical modeling, British Health authorities predicted a major resurgence of measles in school-age children. Two strategies were then examined: either to target vaccination at all children without a history of prior measles vaccination or to immunize all children irrespective of vaccination history.[34] In November 1994, the latter option was chosen and a national measles and rubella vaccination campaign, described as "one of the most ambitious vaccination initiatives that Britain has undertaken" was commenced:[35] within one month, 92% of the 7.1 million schoolchildren in England aged 5–16 years received measles and rubella (MR) vaccine.[36]