Characterisation of a wild-type influenza (A/H1N1) virus strain as an experimental challenge agent in humans

Table 3 Summary of lab-confirmed illness

Inoculum dose dilution ^a	Number of subjects	% rRT-PCR positive ^b	% Sero-converted ^c	% Clinical illness (mild) ^d	% Clinical illness (mod-erate) ^e	% Lab-confirmed *mild* illness ^f	% Lab-confirmed *moderate* illness ^f
1:1000	5	20	40	40	20	20	20
1:100	12	41.6	50	75	41.6	66	41.6
1:10	12	75	50	100	58.3	75	50

^aNeat virus was 3.5 × 10⁷ TCID_50.
^bAssessed using a rRT-PCR assay.
^cSeroconversion defined as a fold increase in serum HI titres of ≥4.
^dMild clinical illness defined as one mild physician-reported sign or subject-reported symptom.
^eModerate clinical illness defined as one moderate physician-reported sign or subject-reported symptom.
^fLab-confirmed illness defined as mild or moderate clinical illness + positive rRT-PCR result or seroconversion or both.

ISSN: 1743-422X