Human hypersensitivity to a sham vaccine prepared from mosquito-cell culture fluids.

A sham vaccine, prepared with the C6/36 cell line derived from larval Aedes albopictus mosquitoes, was skin tested on 12 volunteers. Although no reactions were observed after prick tests, three immediate reactions did occur after intradermal tests. Subcutaneous administration of the C6/36 sham vaccine was initially performed on the nine subjects who did not demonstrate immediate reactions. Five of these subjects developed delayed reactions at the site of the intradermal test within 12 hr after inoculation. A Prausnitz-Küstner test was performed on the back of one unsensitized subject by use of both unheated and heated sera from three subjects who had immediate skin reactions, three who demonstrated a delayed reaction, and one who had a negative skin response. In the Prausnitz-Küstner test, immediate skin reactions were observed with all seven unheated sera but with none of the heated serum aliquots. The determination that skin reactivity was associated with a heat-labile serum factor suggested the mechanism was IgE-mediated. Under close surveillance, the C6/36 sham vaccine was administered subcutaneously to one volunteer who had previously demonstrated an immediate response. This subject developed an anaphylactic reaction characterized by hives at the site and more distantly from the site of the subcutaneous inoculation. Hypersensitivity to A. albopictus larval antigens is common and precludes the use of C6/36 cell culture as a substrate for viral vaccines.

RCT Entities:   Population Interventions Outcomes