The Expanded Program on Immunization (EPI) was initiated in 1974 in The Ame
ricas, based on the WHA 2757 resolution passed by the World Assembly of Hea
lth. Its purpose was to improve immunization coverage and to decrease morbi
dity and mortality caused by vaccine preventable diseases through vaccinati
on. Specific goals were to eradicate in determined time periods poliomyelit
is, measles, neonatal tetanus, to eliminate tuberculous meningitis in child
ren four years and younger, diphtheria, and tetanus, to eliminate tuberculo
us meningitis in children four years and younger, diptheria, and tetanus. T
his article presents up to date information on vaccination coverage trends
between 1990 and 1998 in 13 countries of the American Region, briefly descr
ibes implementation of surveillance programs required for appropriate monit
oring of vaccine impact, and discusses the changes observed in morbidity at
tributable to vaccine preventable disease in these countries during four pe
riods, 1968 before the existence of EPI, 1978, four years after its introdu
ction, 1988 and 1998. Although much remains to be done, the impact of EPI i
n the Americas has been outstanding in decreasing morbidity caused by vacci
ne preventable diseases.