3708492 VLPs virus-like particles 3748 1809238 VLP virus-like particle 1701 3713477 VPLs virus-like particles 3 2967091 VLP's virus-like particles 2 2963410 VLiPs virus-like particles 2 259810 LP virus-like particles 1 2970138 VLPSs virus-like particles 1