Pooled sensitivities of IgG (65%) and IgM (62%) were almost identical—precluding their differential use in diagnostic algorithms—and increased in parallel during the course of infection: in week 1 post symptom onset, aggregated sensitivity for IgM and IgG was 25.3 and 13.4% respectively, increasing to 51.8 and 50.1% in week 2 and exceeding 70% only from week 3 onwards (69.9 and 79.8%, respectively), with high variations between different products (11). This evidence concerns the gene CD40LG and infection.