Neutralization of a togavirus by antivector antisera

An A. aegypti-propagated togavirus (Sindbis) is neutralized by antisera to both whole-body extracts and to salivary fluid of the vector mosquito. Virus propagated in Vero cells is not neutralized by such antisera. Neutralizing activity resides in the immune globulin fraction of sera. Sera from animals injected with adjuvant neutralized neither virus propagated in mosquitoes nor virus obtained from Vero cells. Although neutralizing titers were low, such activity may protect, to some degree, vertebrate hosts normally exposed to vector antigens.