Fig. 1.

Incidence of confirmed measles cases in Viet Nam by province, before (2001) and (2003 in the north, 2004 in the south) after the mass measles immunization campaign^a

^a The nationwide mass immunization campaign was conducted in the north of Viet Nam in 2002 and in the south in 2003. 2001 data were analysed for before the campaign.

^b The horizontal line on the right-hand map indicates the division of the country into the north and south zones.