The vaccination of h uman beings with live avirulent vaccine of Trypanosoma cruzi: A two year follow-up of the first two cases

Abstract

A two year follow-up of the first two volunteers vaccinated icith the live PF T rypanosom a cruzi INTRODUCTIONThe probable m u ta n t of th e Trypano soma cruzi Y s tra in th a t h as been de m o n stra te d to be av iru len t for laboratory anim als (M enezes,10-n . 12. 14-S antos,16 and Hungererß) seems to be av iru len t for h u m an beings as well.In a p relim inary rep o rt (M enezes13) the follow-up studies on the 2 volunteers, w ithin th e first 3 m o n th s a fte r v accin at ion, are referred to.In th is p ap er we will p resen t th e 2 year post-vaccin atio n observations. MATERIAL AND METHODSTwo m ale volunteers, one 52 years old (P a tie n t 1) an d th e o th er 32 years old (P atie n t 2) were vaccinated w ith two do ses of th e live T. cruzi vaccine, PF strain. The two doses were sep arated by a forty day in terv al. The first h ad alm ost 5xl04 p arasites and th e second 3x107 flagellates, and both were injected subcutaneously (M enezes13) .Before vaccination, and 8, 15 and 30 days a fte r each vaccine, an d alm ost once a m o n th th ere after, for two years, ECG, perip h eral blood-search for parasites, blood culture for trypanosom es, CFT (G uerreiro & M achado t e s t ) , Im unnofluorescence Test (IFT) for T. cruzi, X enodiagnosis and blood innoculations in young mice were carried out (Tables 1 & 2) .O ther tests were perform ed during the first 3 m onths, as already m entioned (Me nezes13) .H em ogram and blood sedim entation ra te (BSR) tests were done 8, 15 and 30 * XJSP. D e p a rta m e n to de G en ética e M a tem átic a ap lic a d a à B iologia. F acu ld ad e de M ed icin a. R ibeirão P r e t o . S . P a u lo . B ra s il.