TABLE 2.

Levels of replication, immunogenicity, and efficacy of chimeric bovine-human PIV3s in rhesus monkeys

Immunizing virusaGroup sizebMean peak PIV3 titer (log10 TCID50/ml ± SE)cMean of sum of daily titers (log10 TCID50/ml ± SE)dPostimmuni- zation serum HPIV3 HAI antibody titereMean peak challenge HPIV3 titer (log10 TCID50/ml) tof:Postchallenge serum HPIV3 HAI antibodyg
NPTLNPTLNPTLTiterGroup size
rHPIV3 wt124.2 ± 0.43.5 ± 0.321.2 ± 1.7 A10.5 ± 1.18.6 ± 0.41.4 ± 0.31.1 ± 0.211.5 ± 0.36
rHPIV3-LB43.0 ± 0.83.5 ± 0.211.8 ± 2.4 B, C, D10.5 ± 1.010.3 ± 0.50.9 ± 0.21.5 ± 0.110.8 ± 0.64
rHPIV3-MB43.0 ± 0.63.4 ± 0.616.6 ± 3.7 A, B11.8 ± 2.37.8 ± 0.91.4 ± 0.91.2 ± 0.411.0 ± 0.44
rHPIV3-FB HNB62.7 ± 0.22.7 ± 0.413.5 ± 0.9 B, C9.1 ± 2.14.7 ± 0.62.6 ± 0.21.8 ± 0.511.0 ± 0.04
rHPIV3-NB82.6 ± 0.62.0 ± 0.414.5 ± 2.7 B6.0 ± 1.27.5 ± 0.42.1 ± 0.41.2 ± 0.210.0 ± 0.02
rHPIV3-LBT1711I82.2 ± 0.21.4 ± 0.28.7 ± 0.3 C, D4.4 ± 0.69.8 ± 0.30.9 ± 0.11.6 ± 0.110.8 ± 0.54
rHPIV3-PB61.2 ± 0.21.5 ± 0.36.2 ± 0.3 D5.3 ± 1.07.2 ± 0.62.4 ± 0.52.2 ± 0.610.4 ± 0.54
BPIV3 Kansas122.5 ± 0.22.1 ± 0.214.2 ± 1.1 B6.4 ± 0.85.1 ± 0.52.9 ± 0.22.0 ± 0.511.0 ± 0.02
RSV or none4NANANANA<2.0 ± 0.05.0 ± 0.35.0 ± 0.311.5 ± 0.52
  • a Animals were inoculated i.n. and i.t. on day 0 with 105 TCID50 of the indicated virus per site.

  • b Includes data collected from similarly infected and sampled rhesus monkeys from two previous studies (1, 32). The published data included 6 of the 12 rHPIV3 wild-type animals, 2 of the 6 rHPIV3-FB HNB animals, 6 of the 8 rHPIV3-NB animals, and 6 of the 12 BPIV3 animals.

  • c NP swab samples were collected on days 1 to 10 postinfection. TL samples were collected on days 2, 4, 6, 8, and 10 postinfection. Data are the means of the peak virus titer for each animal in its group irrespective of sampling day. The limit of detection of virus titer was 10 TCID50/ml. NA, not applicable.

  • d The sum of the viral titers obtained for each animal on all sampling days was calculated, and a mean ± SE for each group was generated. Data are the means of sum (log10) daily titers for all animals in each group for NP (days 1 to 10) and TL (days 2, 4, 6, 8, and 10) samples. The lower limit of detection is 5.0 for NP swabs and 2.5 for TL samples. Means of sum titers were assigned to similar groups by the Fisher's PLSD test. Mean titers with different letters are statistically significantly different (P < 0.05). Titers indicated with two or three letters are not significantly different from those indicated with either letter.

  • e Postinfection HAI data includes data from animals from the present study and from previous studies (1, 32). Sera were collected 28 to 31 days postinfection and titers were determined in the same assay, with the exception of the sera from groups that received rHPIV3LBT1711I and rHPIV3 LB, in which titers were determined in a second assay along with those in control sera from the first assay. The values obtained with the control sera in the second assay were similar to those obtained in the first assay.

  • f Animals were challenged i.n. and i.t. on day 28 or 31 post-first immunization with 106 TCID50 of the JS strain of HPIV3 wild type per site. NP swab and TL samples were collected on days 2, 4, 6, 8, and 10 postinfection. Virus titrations were performed on LLC-MK2 cells at 32°C. Mean of the peak virus titers ± SE for each animal in its group irrespective of sampling day is shown. The limit of detection of virus titer was 10 TCID50/ml. Results include data from the present study and data from previous studies (1, 32).

  • g Postchallenge antibody titers were obtained 28 days postchallenge for a subset of animals whose numbers are indicated in the last column. This does not include animals from references 1 and 32. The titers in sera from animals in this subset were determined in the same assay, with the exception of sera from the groups that received rHPIV3LB T1711I and rHPIV3 LB, in which titers were determined in a separate assay along with those in control sera from the first assay. The values obtained with the control sera in the second assay were similar to those obtained in the first assay.