Samples used for analysis (see text).

<p>Samples collected at study enrollment were available for 2,561 (76.8%) of the 3,335 women enrolled in the PEPI-Malawi trial. The figure shows the number of samples available for analysis using the BED assay (BED), the avidity assay (avidity index, AI) and the HRM diversity assay (HRM) at enrollment and follow-up (12–24 months after enrollment). Different subsets of women were evaluated, including women identified as recently infected at enrollment using the multi-assay algorithm (MAA recent), women identified as not recently infected at enrollment using the MAA (MAA non-recent), and women who were known to have non-recent HIV infection at enrollment (known non-recent).