Table 3 Vaccine protection against different prevailing H9N2 influenza viruses.

From: Generation and protective efficacy of a cold-adapted attenuated avian H9N2 influenza vaccine

Virus

Vaccination

Group

Virus shedding in oropharynx (days post challenge) a

Virus shedding in cloaca (days post challenge) a

3

5

7

3

5

7

A/chicken/Beijing/3/1999

−

Inoculated

10/10 (3.5 ± 0.7) b

10/10 (2.5 ± 0.4)

0/10

8/10 (1.8 ± 0.3)

0/10

0/10

Contact

5/10(1.8 ± 0.4)

0/10

0/10

0/10

0/10

0/10

+

Inoculated

0/10

0/10

0/10

0/10

0/10

0/10

Contact

0/10

0/10

0/10

0/10

0/10

0/10

A/chicken/Hebei/0617/2007

−

Inoculated

10/10 (4.5 ± 0.7)

10/10 (3.8 ± 1.0)

1/10 (1.8)

7/10 (1.2 ± 0.5)

3/10 (1.8 ± 0.2)

0/10

Contact

10/10 (4.8 ± 0.9)

10/10 (5.1 ± 0.8)

10/10 (3.8 ± 0.4)

7/10 (1.5 ± 0.4)

0/10

0/10

+

Inoculated

0/10

0/10

0/10

0/10

0/10

0/10

Contact

0/10

0/10

0/10

0/10

0/10

0/10

A/chicken/Shandong/ZB/2007

−

Inoculated

10/10 (4.5 ± 0.6)

10/10 (3.8 ± 0.8)

5/10 (1.8 ± 0.5)

7/10 (1.3 ± 0.7)

3/10 (1.6 ± 0.6)

0/10

Contact

10/10 (4.1 ± 0.8)

10/10 (4.5 ± 0.6)

10/10 (2.4 ± 0.8)

6/10 (1.2 ± 0.7)

4/10 (1.8 ± 0.7)

0/10

+

Inoculated

3/10(1.5 ± 0.2)

0/10

0/10

4/10(1.5 ± 0.4)

0/10

0/10

Contact

0/10

0/10

0/10

0/10

0/10

0/10

A/chicken/Hebei/YT/2010

−

Inoculated

10/10 (6.3 ± 1.0)

10/10 (4.8 ± 0.8)

6/10 (2.8 ± 1.0)

10/10 (3.7 ± 0.8)

10/10 (3.5 ± 0.7)

6/10 (1.5 ± 0.8)

Contact

10/10 (5.7 ± 0.8)

10/10 (5.3 ± 0.7)

8/10 (3.5 ± 0.7)

10/10 (2.8 ± 0.5)

10/10 (1.8 ± 0.9)

7/10 (2.5 ± 0.6)

+

Inoculated

0/10

0/10

0/10

0/10

0/10

0/10

Contact

0/10

0/10

0/10

0/10

0/10

0/10

A/chicken/Guangdong/01/2011

−

Inoculated

10/10 (5.8 ± 0.7)

10/10 (3.8 ± 0.6)

4/10 (1.8 ± 0.7)

10/10 (2.5 ± 0.7)

6/10 (2.8 ± 0.5)

0/10

Contact

10/10 (3.8 ± 0.8)

10/10 (4.5 ± 1.0)

3/10 (4.5 ± 0.8)

10/10 (1.8 ± 0.6)

3/10 (1.5 ± 0.3)

0/10

+

Inoculated

0/10

0/10

0/10

0/10

0/10

0/10

Contact

0/10

0/10

0/10

0/10

0/10

0/10

A/chicken/Shandong/sd01/2010

−

Inoculated

10/10 (5.7 ± 0.8)

10/10 (3.5 ± 0.9)

3/10 (1.5 ± 0.4)

10/10 (2.7 ± 0.9)

4/10 (2.5 ± 0.6)

3/10 (1.8 ± 0.4)

Contact

10/10 (5.3 ± 0.5)

10/10 (4.3 ± 0.7)

6/10 (2.5 ± 0.6)

10/10 (2.8 ± 0.7)

7/10 (1.8 ± 0.9)

0/10

+

Inoculated

0/10

0/10

0/10

0/10

0/10

0/10

Contact

0/10

0/10

0/10

0/10

0/10

0/10

  1. aGroups of 3-week-old SPF white Leghorn chickens were immunized intranasally with 0.2 mL 106 EID50 of cold-adapted H9N2 viruses or phosphate-buffered saline (mock immunized). Chickens were challenged intranasally with 106 EID50 of the homologous or heterologous viruses on day 14 post immunization. At 24 h after challenge, in-contact chickens were placed in physical contact with challenged birds. Virus titers in oropharyngeal and cloacal swabs on 3, 5, and 7 days post challenge were determined.
  2. bNo. of chickens positive for virus/total no. of chickens tested (mean titers [log10 EID50/mL] ± standard errors).
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