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Table 1 Overview of HI titers at challenge, virus isolation data, clinical symptoms, and mortality rates

From: A single vaccination of commercial broilers does not reduce transmission of H5N1 highly pathogenic avian influenza

  Number of birds
  Mean HI titer (absolute (sd)) with HI titer ≥ 2^5 at challenge shedding virus a with clincial symptoms that died
Exp. Treatment at challenge ( 2 log) at end d ( 2 log) I b C b I C I C I C
1 no vaccination challenge at d28 of age 1.6 (1.0) 206 (457) 0 0 22 19 22 22 22 16
2 vaccination at d1 challenge at d28 of age 1.7 (1.3) 166 (381) 0 0 22 18 19 16 16 15
3 vaccination at d10 challenge at d28 of age 1.8 (0.9) 251 (357) 0 0 18 15 16 10 13 7
4 no vaccination challenge at day 1 of age 4.9 (1.2)c 1.0 (0.4)f Ndc nd 16 6 19 19 13 1
  1. a total numbers in each group were 22 inoculated chickens and 22 contact-exposed chickens.
  2. b I: inoculated chickens; C: contact-exposed chickens.
  3. c not determined.
  4. d only from surviving and infected birds.
  5. e from surplus birds.
  6. f one bird had a titer of 1024, which is omitted from this average.