Fig. 3. Viral RNA in plasma samples and serological responses in lambs of the RTV study.

Monitoring of viremia (a) in lambs of Group 1 (vaccinated) by RT-qPCR. Samples that tested negative are depicted at the detection limit of the PCR (1.3 log₁₀ RNA copies/ml). Results of Group 2 (first animal passage) are not depicted as no viral RNA was detected in plasma samples from these animals. Detection of viral RNA (b) in organ samples (3 days post vaccination) of lambs from Group 1. Results of Group 2 are not depicted as no viral RNA was detected in organ samples from Groups 2A (3 DPV) and 2B (21 DPV). LN lymph node. Detection of anti-N antibodies (c) by ELISA in weekly obtained sera of lambs from Group 2B. Titres are expressed as percentage inhibition ratio of the optical densities (OD) of the sample and the OD of the negative control (% S/N). All values lower than 40% are considered positive, between 40 and 50% are considered doubtful and above 50% are considered negative. Measurements were taken from distinct samples. Error bars represent s.d.