Neutralization of Sindbis virus by antisera to antigens of vector mosquitoes

Sindbis virus harvested from infected cultures of Vero cells and from Aedes aegypti mosquitoes was used in neutralization tests with sera obtained from guinea pigs immunized with ground A. aegypti and from guinea pigs repetitively bitten by mosquitoes. Employing these antisera, more mosquito-propagated virus was neutralized than was virus grown in cultures of Vero cells. The neutralizing activity resided in the immune globulin fraction and may reflect the production of antibody to vector antigens on the viral envelope.