Reduced childhood mortality after standard measles vaccination at 4-8 months compared with 9-11 months of age

BMJ. 1993 Nov 20;307(6915):1308-11. doi: 10.1136/bmj.307.6915.1308.


Objective: To evaluate the impact on mortality of standard Schwarz measles immunisation before 9 months of age.

Design: Children vaccinated in 1980-3 at 4-5, 6-8, and 9-11 months of age were followed to migration, death, or the age of 5 years.

Setting: One urban district and nine villages in two rural areas of Guinea-Bissau.

Subject: 307 children vaccinated at 4-8 months and 256 at 9-11 months.

Main outcome measures: Mortality from 9 months to 5 years of age for children immunised at 4-5, 6-8, and 9-11 months.

Results: Mortality was significantly lower in children vaccinated at 6-8 months than at 9-11 months (mortality ratio = 0.63, (95% confidence interval 0.41 to 0.97), p = 0.047). As vaccination was provided in semiannual or annual campaigns it is unlikely that age at vaccination reflected a selection bias. The trend was the same in all three study areas. Improved survival after early immunisation was not related to better protection against measles infection. With a Cox multivariate regression model to adjust for age, sex, season at risk, season at birth, measles infection, and region, children vaccinated at 4-8 months had a mortality ratio of 0.61 (0.40 to 0.92, p = 0.020) compared with children vaccinated at 9-11 months. Reimmunised children tended to have lower mortality than children who received only one vaccine (0.59 (0.28 to 1.27, p = 0.176)).

Conclusion: Standard measles vaccination before 9 months is not associated with higher childhood mortality than is the currently recommended strategy of immunising from 9 months, and it may reduce mortality. This has implications for measles immunisation strategy in developing countries.

PIP: In 1980-83, health workers followed children living in urban Bandim district or in the rural regions of Oio and Quinhamel in Guinea-Bissau to death, migration, or to age 5 to compare mortality of 307 of the children who were vaccinated against measles at 4-8 months with the mortality of the remaining 256 children who were vaccinated against measles at 9-11 months. Health workers conducted the vaccination campaigns on an annual or semiannual basis, so age at vaccination probably did not pose a selection bias. Children vaccinated at 6-8 months were significantly less likely to die than those vaccinated at 9-11 months (mortality ratio [6-8 months/9-11 months] = .63; p = .047). Child survival was much higher in the 6-8 month group than the 9-11 month group in all 3 areas. When researchers adjusted for age, sex, season at risk, season at birth, measles infection, and region, child survival was significantly better in children vaccinated against measles at 4-8 months than it was at 9-11 months (mortality ratio = .61; p = .02). Children who were reimmunized died less often than those who were immunized only once (mortality ratio - .59), but the difference was not significant. These findings suggested that measles vaccination before 9 months of age plus reimmunization result in better childhood survival than does 1 measles vaccination at 9-11 months of age (the current recommended strategy for measles immunization). The researchers stress the need for more research on longterm survival after measles immunization at different ages and reimmunization.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Developing Countries*
  • Female
  • Follow-Up Studies
  • Guinea-Bissau / epidemiology
  • Humans
  • Immunization Schedule*
  • Infant
  • Male
  • Measles / prevention & control*
  • Measles Vaccine / administration & dosage*
  • Mortality*
  • Socioeconomic Factors
  • Vaccination*


  • Measles Vaccine