Biochemical and immunologic comparison of virus-like particles for a rotavirus subunit vaccine

A parenterally administered rotavirus vaccine composed of virus-like partic les (VLPs) is being evaluated for human use. VLPs composed of bovine VP6 an d simian VP7 (SA11, G3) proteins (6/7-VLPs) or of bovine VP2, bovine VP6, a nd simian VP7 (SA11, G3) proteins (2/6/7-VLPs) were synthesized and purifie d from Sf9 insect cells co-infected with recombinant baculoviruses. 6/7- an d 2/6/7-VLP administered parenterally (i.m.) in mice had comparable immunog enicity, but the 2/6/7-VLPs were more homogeneous and stable. The inclusion of the VP2 capsid contributed to particle formation and stability. The adj uvant QS-21 significantly enhanced the immunogenicity of 2/6/7-VLPs over A1 0H or saline alone. Equivalent serum neutralizing antibody responses were i nduced over the range of 1-15 mu g/dose of 2/6/7-VLPs administered with the range of 5-20 mu g/dose of QS-21. The immunogenicity of 2/6/7-VLPs and ina ctivated SA11 virus were comparable. 2/6/7-VLPs are a promising candidate f or a parenterally delivered rotavirus subunit vaccine. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.