Fig 2 Number of deaths by month, July 2002 to May 2006 (numbers should be interpreted with caution as number of enrolled children and their average age changed over time). Sequence of events: recruitment to trial started in July 2002; oral polio vaccine and vitamin A supplementation campaign (high coverage) occurred in October and November 2002; malaria survey and iron supplementation in August and November 2003; measles epidemic in November 2003-May 2004; missed vaccines and vitamin A supplementation campaign (low coverage) in November 2003; recruitment stopped in April 2004; oral polio vaccine and vitamin A supplementation campaign (high coverage) took place in October and November 2004, and October and November 2005; measles vaccine for all aged <15 and vitamin A supplementation campaign (high coverage) and end of follow-up was in May 2006