A comparison of vaccine efficacy and mortality during routine use of high-titre Edmonston-Zagreb and Schwarz standard measles vaccines in rural Senegal.
Vaccine efficacy and mortality in successive cohorts of children who routinely received either Edmonston-Zagreb high-titre (EZ-HT) or Schwarz standard (SW-STD) measles vaccines have been examined in a rural area of Senegal. The 2 vaccines were equally protective against measles infection (vaccination efficacy: EZ-HT 94%; SW-STD 93%). Children who did not attend a scheduled session to receive measles vaccine had a higher mortality rate between 9 months and 2 years of age than did children receiving either EZ-HT (mortality ratio [MR] = 1.81, 95% confidence interval [CI] 1.06-3.08) or SW-STD measles vaccine (MR = 1.74, 95% CI 0.95-3.21). Children of either sex vaccinated with EZ-HT had lower mortality than their equivalents who had not received any measles vaccine. There was no difference in overall mortality between recipients of EZ-HT and SW-STD (MR = 0.96, 95% CI 0.70-1.30). Using a Cox regression analysis to adjust for sex, age and significant background factors (season and death of mother), mortality rates tended to be lower for male recipients of EZ-HT than for boys receiving SW-STD (MR = 0.73, 95% CI 0.50-1.11) and higher for girls receiving EZ-HT than for girls receiving SW-STD (MR = 1.30, 95% CI 0.81-2.09) (test of interaction between sex and vaccine, P = 0.067). The tendency to reduced survival benefit for girls following receipt of high-titre measles vaccines substantiated observations from randomized trials in Guinea-Bissau, Senegal and Haiti. Existing data provide little support for the notion that high-titre vaccine is deleterious but it may not have the same beneficial effects as standard-titre measles vaccine.
Aaby
P
P
UR Maladies Infectieuses et Parasitaires, ORSTOM, Dakar, Senegal.
Samb
B
B
Simondon
F
F
Knudsen
K
K
Seck
A M
AM
Bennett
J
J
Markowitz
L
L
Whittle
H
H
D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008457:Measles / Q000401:mortality / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage / Q000009:adverse effects*; D010349:Patient Compliance; D012044:Regression Analysis; D012423:Rural Health; D012675:Senegal / Q000453:epidemiology; D017678:Sex Distribution; D016019:Survival Analysis; D016896:Treatment Outcome
D008458:Measles Vaccine