Table 1. .

Vaccine Virus Shedding, Peak Virus Titers, and Clinical Assessment During the First 28 Days After Inoculation

			Viral Detectiona		No. (%) With Indicated Symptomb
Group	No. of Children	No. (%) Shedding Vaccine Virusc	Plaque Assay, Log10 PFU/mLd	RT-qPCR, Log10 Copies/mLe	Fever	URI	LRI	Cough	OM	Respiratory or Febrile Illness
Vaccine	11	4 (36%)	1.6 (0.5–3.4)	4.5 (1.7–6.8)	2 (18)	6 (55)	2 (18)	4 (36)	3 (27)	7 (64)
Placebo	6	0	0.5 (0.5–0.5)	1.7 (1.7–1.7)	4 (67)	6 (100)	0 (0)	4 (67)	0 (0)	6 (100)

Abbreviations: LRI, lower respiratory illness, defined as wheezing, rhonchi, or rales, or having been diagnosed with pneumonia or laryngotracheobronchitis (croup); NW, nasal wash; OM, acute otitis media; PFU, plaque-forming unit; RT-qPCR, reverse transcription quantitative polymerase chain reaction; RSV, respiratory syncytial virus; URI, upper respiratory illness, defined as rhinorrhea, pharyngitis, or hoarseness.

^aMedian (25th–75th percentile) peak viral titers detected in nasal washes. For the vaccine group, these summaries were calculated only for the 6 children who were infected with vaccine virus; infection was defined as the detection of vaccine virus by culture and/or RT-qPCR and/or a ≥4-fold rise in RSV serum-neutralizing antibody titer and/or serum anti-RSV F antibody titer. As expected, no placebo recipients shed vaccine virus.

^bNumber (%) of children with indicated respiratory symptoms occurring in the 28 days after inoculation.

^cPercentage of children with vaccine virus detected in NW by culture and/or RT-qPCR. Three children had vaccine virus detected by both culture and PCR, and 1 only by RT-qPCR.

^dFor each child, the individual peak (highest) titer, irrespective of day, was selected from among all titers measured in the NW by viral culture and expressed as log₁₀ PFU/mL. The lower limit of detection was 0.5 log₁₀ PFU/mL.

^eFor each participant, the individual peak (highest) titer, irrespective of day, was selected from among all titers measured in NW by RT-qPCR and expressed as log₁₀ copies/mL. The lower limit of detection was 1.7 log₁₀ copies/mL.