This represented the average time when a case would become affected. The model was also used to estimate VE against severe disease, i.e. severe enough for an animal to stop eating or where oral lesions had a combined diameter of greater than 50% of the width of the hard palate (approximately). VE against infection was calculated. An animal was
learn more considered infected during the outbreak if it tested positive for both NSP antibodies (>50% percentage inhibition, standard cut off) and Asia-1 structural protein (SP) antibodies (reciprocal titre >32, standard cut off), the former tested using the PrioCHECK FMDV NS ELISA (Prionics, Zurich, Switzerland) and the latter by titration with the Asia-1 Liquid Phase Blocking ELISA (The Pirbright Institute, UK). There is some uncertainty over the relative reactivity of the LPB ELISA, which uses the Asia-1 Shamir antigen, with cattle vaccinated with the Shamir vaccine and infected or vaccinated with the Sindh-08 strain. The possibility of low sensitivity due to differences in the field virus and the ELISA antigen provided a further reason for using the 1:32 titre cut-off and not
higher. Testing was performed at the Şap institute, Ankara, Turkey. The relationship between within-group incidence and within-group vaccine coverage was investigated. Preliminary analysis was done in R [10] with the lme4 package [11], while the Bayesian analysis was implemented in OpenBUGS selleck chemicals llc [12]. why Vaccine matching tests had previously been done at WrlFMD. r1-Values
were 0.13–0.27 for the Shamir vaccine and >0.81 for the TUR 11 vaccine with the Sindh-08 field strain (an r1-value <0.3 suggests poor vaccine match) [6]. All vaccine batches are routinely tested to ensure that they elicit an “adequate” immune response. Tested at point of production in five cattle, 28 days after vaccination with a single dose, cattle had a mean virus neutralisation reciprocal titre of 24 for both vaccine batches used at Ardahan and Denizli, 29 for the batch used in Afyon-1 and 34 for the two batches used at Afyon-2 (assessed against vaccine homologous virus). The cut-off titre for protection found in challenge studies was 16 (as per OIE guidelines [13]). Post-vaccination immune response was also assessed during the investigations in cattle not affected by or exposed to FMD. In total, 1377 cattle were included in the study of which 1230 were over four months of age. The cattle included in the four investigations were from 134 management groups from 97 different holdings in 12 villages. Typically, almost all households in a village would own some cattle (inter-quartile range 5–15 cattle per holding). See Fig. 2 for the age-sex structure. Oral examination was performed on 82% (611/742) of cattle ≤24 months and 42% (207/488) of cattle >24 months of age. All (724/724) cattle ≤24 months were blood sampled and 99% (484/488) of those >24 months.