TABLE 1.

HA content in influenza VLPsa

VaccineProtein (mg/ml)HA titers (±SD) in VLPs or virusRatio of HA titers/μg protein (±SD)Ratio of HA/total protein (μg) (±SD)b
Influenza VLPs3.540,960 ± 8,865234 ± 520.10 ± 0.02
Inactivated A/PR84138,6006930.29
  • a HA titers are shown in geometric mean values from three independent experiments of influenza VLPs (3.5 mg/ml).

  • b HA content was estimated based on the observation that influenza virus HA makes up approximately 29% of the total protein of purified virus (33).