Table 1.
Response of adults to RSV wild-type or to RSV B1 cp-52 mutant virus and of infants and children to RSV B1 cp-52 or placebo
| Subjects | RSV B1 administered | Dose (log10 pfu) | No. of subjects | % Infected | Virus isolation, nasal wash
|
% with indicated illness
|
Serum neutralizing antibody titer, reciprocal mean (SD) log2
|
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % Shedding virus | Peak titer, mean (SD) log10 pfu/ml | Febrile | URI | LRI | OM | Any RSV-like | Pre | Post | % with rise | |||||
| Adults | wt | 4.7 | 19 | 53 | 53 | 3.1 (1.3) | 5 | 21 | 0 | 0 | 26 | 10.2 (1.2) | 10.6 (0.9) | 6 |
| cp-52 | 5.0 | 17 | 6 | 6 | 1.9† | 6 | 0 | 0 | 0 | 6 | 9.3 (0.8) | 9.4 (0.9) | 0 | |
| Sero + | cp-52 | 4.0 | 4 | 25 | 25 | ≤0.6* | 75 | 50 | 0 | 0 | 75 | 9.1 (0.8) | 8.5 (0.7) | 0 |
| children | cp-52 | 5.0 | 11 | 45 | 45 | 0.9† (0.6) | 9 | 18 | 0 | 0 | 27 | 9.9 (1.6) | 9.7 (1.4) | 0 |
| Placebo | 0.0 | 7 | 0 | 0 | ≤0.6 | 14 | 0 | 0 | 0 | 14 | 10.2 (1.9) | 9.7 (1.8) | 0 | |
| Sero − | cp-52 | 4.0 | 7 | 14 | 14 | 1.3† | 28 | 14 | 0 | 14 | 28 | 4.3 (0.1) | 4.3 (0.1) | 0 |
| children | cp-52 | 5.0 | 9 | 11 | 11 | 1.9† | 22 | 56 | 0 | 22 | 67 | 4.4 (0.3) | 4.4 (0.3) | 0 |
| Placebo | 0.0 | 10 | 0 | 0 | ≤0.6 | 20 | 30 | 0 | 10 | 50 | 4.3 (0.1) | 4.4 (0.2) | 0 | |
Healthy adults, 15- to 59-month-old RSV seropositive and 6- to 24-month-old RSV seronegative children were enrolled in these studies. For the purposes of this study, seropositive children were those with an RSV serum plaque reduction neutralizing antibody titer >1:40. URI, upper respiratory tract illness; LRI, lower respiratory tract illness; OM, otitis media.
This patient shed vaccine virus that did not plaque.
One adult, one seropositive child, and two seronegative children shed vaccine virus in titers ranging from 101.3 to 102.1 pfu/ml. Attempts to recover vaccine virus from snap-frozen nasal wash specimens by serial passage in Vero cell culture were unsuccessful, probably because low titers of virus were shed.