- Cohort 2: Approximately one hundred and seventy-five (175) subjects will be randomized and dosed as follows: fifty-six (56) subjects with the medium non-adjuvanted dose quadrivalent VLP vaccine, fifty-six (56) subjects with the lowest adjuvanted dose quadrivalent VLP vaccine, nineteen (19) subjects with the highest adjuvanted dose quadrivalent VLP vaccine, nineteen (19) subjects with the highest non-adjuvanted dose quadrivalent VLP vaccine and twenty-five (25) subjects with a placebo. The 7-day safety data after the immunization will be collected by the clinical staff and reviewed by the DSMB prior to allowing immunization of the third cohort.