The development of an AIDS mucosal vaccine

Abstract

Mucosal vaccination offers great advantage for inducing protective immune response at the sites of viral transmission. A novel replication-competent modified vaccinia Tian Tan (MVTT) is an attenuated variant of the wild-type VTT, which was historically used as a smallpox vaccine for millions of people in China. MVTT was generated through genetic engineering and clonal selection of VTT and exhibited excellent safety profiles for mucosal inoculation. The spike glycoprotein (S) of SARS-CoV was used as a test antigen after the S gene was constructed in the identical genomic location of two live vectors to generate vaccine candidates MVTT-S and MVA-S. A head-to-head comparison has been conducted in mice for inducing neutralizing antibodies (Nabs) via mucosal vaccination. Our results indicated that MVTT is superior to MVA for inducing high levels of systemic Nab response post mucosal vaccination. Moreover, a candidate vaccine MVTTSIVgpe, which expresses three major viral structural proteins of simian immunodeficiency virus, has been recently characterized in vitro. The efficacy of MVTT-SIVgpe will be further evaluated in a highly pathogenic SIV/Chinese macaque model.