Child mortality following standard, medium or high titre measles immunization in West Africa.

Knudsen,-K-M; Aaby,-P; Whittle,-H; Rowe,-M; Samb,-B; Simondon,-F; Sterne,-J; Fine,-P

Int-J-Epidemiol. 1996 Jun; 25(3): 665-73

International-journal-of-epidemiology

BACKGROUND. The World Health Organization (WHO) recommended the use of high titre measles vaccine in 1989. Subsequent long term follow-up of several trials yielded results suggesting higher mortality among children inoculated with medium and high titre vaccines compared to standard titre vaccines, although none of the individual trials found significant differences in mortality. METHODS. Long term survival after standard, medium and high titre measles vaccines has been investigated in a combined analysis of all West African trials with mortality data. In trials from Guinea-Bissau, The Gambia and Senegal, children received medium or high titre vaccines from 4 months of age and were compared to control groups recruited at the same time later receiving standard titre vaccine from 9 months of age. All children were followed up to at least 3 years old. RESULTS. Combining trials of high titre vaccines showed higher mortality among the high titre group compared to the standard group: mortality ratio (MR) = 1.33 (95% CI : 1.02-1. 73). Mortality among recipients of medium titre vaccines was not different from that in the standard vaccine group, MR = 1.11 (95% CI: 0.54-2.27). In a combined analysis by sex, the adjusted mortality ratios comparing high titre vaccine with standard vaccine were 1.86 (95% CI : 1.28-2.70) for females and 0.91 (95% CI : 0.61-1.35) for males. The trials were not designed to study long term mortality. Adjustments for several possible sources of bias did not alter the results. CONCLUSIONS. The combined analysis showed a decreased survival related to high titre measles vaccine compared with standard titre vaccines, though solely among females. As a result of these studies from West Africa and a study from Haiti, WHO has recommended that high titre measles vaccine no longer be used.

Successful immunization of infants at 6 months of age with high dose Edmonston-Zagreb measles vaccine. Cite Soleil/JHU Project Team.

Job,-J-S; Halsey,-N-A; Boulos,-R; Holt,-E; Farrell,-D; Albrecht,-P; Brutus,-J-R; Adrien,-M; Andre,-J; Chan,-E; et-al.

Pediatr-Infect-Dis-J. 1991 Apr; 10(4): 303-11

Pediatric-infectious-disease-journal,-The

A group of 2097 Haitian infants 6 to 11 months of age were randomized to receive Schwarz or Edmonston-Zagreb strain measles vaccines containing 10- to 500-fold more vaccine viral particles than standard potency vaccines. No unusual adverse reactions were noted. Edmonston-Zagreb vaccines were more effective than equivalent doses of Schwarz vaccines as measured by the proportion of vaccinated children with measles antibody concentrations greater than or equal to 200 mIU/ml 2 months after vaccination and the persistence of antibody at 18 to 24 months of age. High titer Edmonston-Zagreb vaccine administered at 6 months of age induced antibody concentrations greater than or equal to 200 mIU/ml in 83% of infants by plaque reduction neutralization and 93% of infants by enzyme-linked immunosorbent assay with high rates of antibody persistence at 12 to 24 months of age. The World Health Organization recommends high titer Edmonston-Zagreb measles vaccines for routine use at 6 months of age in areas where measles is an important cause of mortality in young infants.  

Loss of maternal measles antibody in black South African infants in the first year of life--implications for age of vaccination.

Kiepiela,-P; Coovadia,-H-M; Loening,-W-E; Coward,-P; Abdool-Karim,-S-S

S-Afr-Med-J. 1991 Feb 2; 79(3): 145-8

South-African-medical-journal

In order to investigate the feasibility of measles vaccination before the age of 9 months the duration of passive immunity against measles was estimated by conducting a longitudinal study of measles antibody levels in 20 black neonates delivered at term. Measles serum antibody (IgG) was measured by enzyme-linked immunosorbent assay in the mother at childbirth and on consecutive samples taken from the infants from birth until 9 months of age. Protective measles antibody level was defined as greater than 200 mIU. Unprotective levels were found in 88% (95% confidence interval (CI) 81-99%) of 6-month-old infants, while at 9 months all were susceptible. The mean antibody level was 192 mIU (CI 104-348%) at 4 months; 34 mIU (CI 15-73%) at 6 months and 13 mIU (CI 6-24%) at 9 months of age. Our data support the recent World Health Organisation recommendation to immunise children in developing countries at 6 months with the 'high titre' Edmonston-Zagreb measles vaccine, since most infants in our study had lost passive immunity against measles by this age.