MSP1-specific memory B cells in blood, determined by a functional ELISpot assay, are also present at very low but detectable levels for similar periods of time, and present in increased numbers following a second infection; again with similar kinetics, but not magnitude, to the response of splenic memory B cells, and remain at persistently low but detectable levels for up to 90 days after a primary infection. Here, ATAD1 is linked to infection.