TABLE 1.

Passage history of MP-12 vaccine

Component	Source	Source vol	Production	Time of harvest (hpia)	No. of 150-cm2 flasksb	Yield
Original MP-12 strainc	Plaque purified clone after 12th mutagenesis	NAd	MRC-5 cells, 1 passage at 37°C	48–72	NA	NA
Master seed	Original MP-12	10−3 dilution, 1 ml/flask	MRC-5 cells, 1 passage at 37°C	51	40	>6.0 log10 PFU/ml (860 ml)
Production seed	Master seed	10−2.5 dilution, 1 ml/flask	MRC-5 cells, 1 passage at 37°C	50	60	>6.0 log10 PFU/ml (1,750 ml)
Vaccine lot 7	Production seed	10−2 dilution, 1 ml/flask	MRC-5 cells, 1 passage at 35°C	62	1,239	58,120 ml
Vaccine lot 7-2-88	Vaccine lot 7	5.5 liters	Filtration, 0.45-μm-pore-size filter			5 log10 PFU/ml, 9,360 vials (5.5 ml) (freeze-dried)

^ahpi, hours postinfection.

^bFifty milliliters per flask.

^cThe production of original MP-12 was described by Caplen et al. (6).

^dNA, data not available.