Measles virus Enders’ Edmonston strain..................................... ≥ 3.00 log10 CCID50* Mumps virus Jeryl Lynn™ (Level B) strain................................ ≥ 4.30 log10 CCID50* Rubella virus Wistar RA 27/ 3 strain............................................ ≥ 3.00 log10 CCID50* Varicella virus Oka/ Merck strain................................................ .≥ 3.99 log10 PFU**