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Table 4 Immunogenicity and protective efficacy of rHPIV1 vaccine candidates in AGMs.

From: Attenuation and efficacy of human parainfluenza virus type 1 (HPIV1) vaccine candidates containing stabilized mutations in the P/C and L genes

     Mean peak challenge virus titer (log10TCID50/ml)c Mean sum of the daily challenge virus titers (log10TCID50/ml)d Post-challenge serum HAI titerb
Virusa No. animals Pre-challenge serum HAI titerb NP swab TL NP swab TL  
1 HPIV1 wt 12 6.7 ± 0.6 (12/12) 0.8 ± 0.2 f 0.7 ± 0.1 2.3 ± 0.2 2.4 ± 0.2 6.6 ± 0.5
2e rHPIV1-CR84G 4 3.8 ± 0.9 (3/4) ≤0.5 ± 0.0 ≤0.5 ± 0.0 ≤2.0 ± 0.0 ≤2.0 ± 0.0 4.4 ± 1.2
3e rHPIV1-CR84GHNT553A 12 6.0 ± 0.6 (11/12) 0.6 ± 0.1 0.6 ± 0.1 2.1 ± 0.1 2.1 ± 0.1 7.9 ± 0.4
4e rHPIV1-CΔ170 6 5.5 ± 0.4 (6/6) ≤0.5 ± 0.0 ≤0.5 ± 0.0 ≤2.0 ± 0.0 ≤2.0 ± 0.0 6.5 ± 0.4
5 rHPIV1-LY942A 4 6.3 ± 1.2 (4/4) 1.1 ± 0.2 1.2 ± 0.2 2.7 ± 0.3 2.8 ± 0.3 8.9 ± 1.1
6e rHPIV1-CR84GHNT553ALY942A 8 2.0 ± 0.0 (3/8) 0.8 ± 0.2 0.8 ± 0.2 2.6 ± 0.3 2.4 ± 0.3 3.3 ± 0.7
7 rHPIV1-CR84GLΔ1710–11 4 6.1 ± 1.8 (3/4) 3.4 ± 0.6 3.0 ± 0.6 8.4 ± 2.0 8.3 ± 1.3 6.9 ± 1.5
8 rHPIV1-CR84G/Δ170HNT553ALY942A 4 ≤1.0 ± 0.0 (0/4) 2.2 ± 0.2 1.8 ± 0.5 5.1 ± 0.3 4.3 ± 1.3 5.5 ± 1.6
9 rHPIV1-CR84G/Δ170HNT553ALΔ1710–11 4 ≤1.0 ± 0.0 (0/4) 4.5 ± 0.9 3.4 ± 0.4 11.8 ± 2.5 8.1 ± 1.3 7.5 ± 1.4
10 Non-immune 7 ≤1.0 ± 0.0 (0/4) 5.0 ± 0.6 3.9 ± 0.5 14.8 ± 1.2 11.0 ± 2.5 6.0 ± 1.3
  1. a Monkeys were immunized i.n. and i.t. with 106 TCID50 of the indicated virus in a 1 ml inoculum at each site and were challenged on day 28 post-infection with HPIV1 wt.
  2. b HAI titers to HPIV1 were determined by HAI assay of sera collected at day 28 (pre-challenge) and day 56 (post-challenge) in separate assays. Titers are expressed as mean reciprocal log2± S.E.; the limit of detection was 1.0 ± 0.0. The number of animals with a 4-fold or greater increase in pre-challenge antibody titers is shown in brackets for each group.
  3. c Mean ± S.E of the individual peak virus titers for the animals in each group irrespective of day. Virus titrations were performed on LLC-MK2 cells at 32°C. The limit of detection was 0.5 log10 TCID50/ml. NP and TL samples were collected on days 2, 4, 6 and 8 post-challenge.
  4. d Mean sum of the daily virus titers: the sum of the titers for all of the days of sampling was determined for each animal individually, and the mean was calculated for each group. On days when no virus was detected, a value of was 0.5 log10 TCID50/ml was assigned for the purpose of calculation. The mean sum of the lower limit of detection was 2.0 log10 TCID50/ml for NP swabs and TL samples.
  5. e These data have been previously published [13] [15] [16] and are included here for the purposes of comparison.
  6. f Underlined values indicate statistically significant reductions in mean peaks or sum of daily virus titers for HPIV1 wt titer compared to the corresponding non-immune group, P < 0.05 (Student-Newman-Keuls multiple comparison test).