Is early measles vaccination associated with stronger survival benefits than later measles vaccination?

Wednesday, 19th of September 2018

 

BMC Public Health. 2018 Aug 7;18(1):984. doi: 10.1186/s12889-018-5866-y.

Is early measles vaccination associated with stronger survival benefits than later measles vaccination?

Hansen JS¹² Thysen SM¹²³ Rodrigues A² Martins C² Fisker AB⁴⁵⁶.

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Abstract

BACKGROUND:

Measles vaccine (MV) may protect against non-measles mortality. We tested whether survival depended on age of measles vaccination.

METHODS:

Bandim Health Project follows children under 5 years of age through a Health and Demographic Surveillance System in rural Guinea-Bissau. Children aged 6-36 months with a vaccination card inspected were followed to the next visit or for a maximum of 6 months. In Cox proportional-hazards models adjusted for age and village cluster we compared the survival of children vaccinated with MV early (< 9 months) as recommended (9-11 months) or late (> 12+ months) with the survival of measles-unvaccinated children. Among measles-vaccinated children we modelled the effect of age at measles vaccination linearly to assess mortality changes per month increase in vaccination age.

RESULTS:

From 1999 to 2006 14813 children (31725 observations) were included. Children vaccinated with MV had a Hazard Ratio (HR) of 0.76 (95% CI: 0.63-0.91) compared with measles-unvaccinated children; censoring measles deaths did not change the results (HR = 0.79 (0.65-0.95)). For early MV the HR was 0.68 (0.53-0.87) for MV as recommended the HR was 0.77 (0.62-0.96) and for late MV the HR was 0.86 (0.67-1.11). Limiting the analysis to measles-vaccinated children age at measles vaccination was associated with a 2.6% (0.4-5.1%) increase in mortality per month increase in vaccination age.

CONCLUSION:

Early MV was associated with a large survival advantage. The current policy to increase vaccination age when measles control improves may not optimize the impact of MV on child survival.

KEYWORDS:

Childhood mortality; Measles vaccine; Non-specific/heterologous effects of vaccines

PMID: 30086732 PMCID: PMC6081866 DOI: 10.1186/s12889-018-5866-y