Cairns M, Ceesay SJ, Sagara I, et al. - A very high level of personal protection against clinical malaria is provided by SMC administered as part of routine national malaria control activities, over 28 days post treatment; the observed protection was comparable to that reported during clinical trials.

• In SMC, children 3–59 months of age are administered two antimalarial drugs, sulphadoxine–pyrimethamine and amodiaquine monthly, during the peak months of malaria transmission.

• The protective effectiveness of SMC treatments against clinical malaria was determined by performing case–control studies.

• Children with confirmed malaria at a health facility were included as cases.

• For each case, chosen were 2 controls from the neighborhood where the case lived.

• Comparison of when cases and controls had most recently received SMC was done to estimate the effectiveness of monthly SMC treatment in preventing clinical malaria.

• In all case–control studies, a high level of protection was provided by SMC against clinical malaria.

• During the first 4 weeks after SMC treatment, reduction in clinical malaria incidence occurred on average by 88%.

• In the period 5–6 weeks post administration, lower protection from SMC was observed. .