Transfer of Anti-Rotavirus Antibodies during Pregnancy and in Milk Following Maternal Vaccination with a Herpes Simplex Virus Type-1 Amplicon Vector

Meier, Anita F.; Suter, Mark; Schraner, Elisabeth M.; Humbel, Bruno M.; Tobler, Kurt; Ackermann, Mathias; Laimbacher, Andrea S.

The main aim of this study was to evaluate a safe RV-specific vaccine based on the non-replicating HSV-1 amplicon vector system to induce protective systemic antibodies in a first attempt. For this, the RV proteins were used in a structural vaccinology approach. The transduction with the RV protein encoding HSV-1 amplicon vector sWa[VP2/6/7] triggered the synthesis of all three encoded RV proteins, VP2, VP6 and VP7, as well as the intracellular assembly of RVLPs in cell culture. The distribution of the viral proteins within the cell resembled the localization of proteins in wild type RV infections. When administered intramuscularly, the RV proteins encoding HSV-1 amplicon vectors induced a strong RV specific antibody response in sera as well as in milk of vaccinated dams. In addition, the antibody response was passed through both the placental and/or lactogenic route to unvaccinated offspring swapped to vaccinated dams. As expected, lactogenic transfer of RV specific IgG did not protect the suckling mice from developing RV symptoms upon challenge. Indications of control of systemic spread were noted but will require more targeted experiments. Although full protection against an oral RV challenge was not achieved and would require both oral and systemic vaccination, the helpervirus-free herpesvirus amplicon vectors used in this study may be rapidly adapted to confer immunity against a whole array of different RVs.