Effect of measles vaccination in infants younger than 9 months on the immune response to subsequent measles vaccine doses: a systematic review and meta-analysis
The Lancet Infectious Diseases·
- DOI
- 10.1016/s1473-3099(19)30396-2
- PMID
- 31548081
- PMCID
- PMC6838663
- OpenAlex
- W2974349981
- Study type
- Systematic review
- Publisher
- Elsevier BV
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The findings support early measles vaccination in high-risk settings, as administering the first dose before 9 months followed by additional doses yields high seropositivity, vaccine effectiveness, and T-cell responses. The clinical significance of the observed lower antibody titers remains uncertain.
Structured evidence summary
Research question
The review examined whether administering the first measles-containing vaccine dose to infants younger than 9 months affects immune responses to later measles vaccine doses.
Study design
This systematic review and meta-analysis searched literature through January 2019 for randomized and quasi-randomized controlled trials, outbreak investigations, and observational studies. Twenty-one studies met inclusion criteria and were analyzed using random-effects meta-analysis where appropriate.
Population and setting
The review focused on infants who received their first measles-containing vaccine dose before 9 months of age, particularly in high-risk settings where early vaccination could reduce measles morbidity and mortality.
Main findings
Pooled data from 13 studies showed 98% seropositivity after two vaccine doses when the first dose was given before 9 months, and 7 studies found sustained T-cell responses regardless of first-dose timing. However, some evidence indicated lower antibody titers after subsequent doses when the first dose was administered before 9 months compared to at or after 9 months.
Public-health relevance
The findings support early measles vaccination in high-risk settings, as administering the first dose before 9 months followed by additional doses yields high seropositivity, vaccine effectiveness, and T-cell responses. The clinical significance of the observed lower antibody titers remains uncertain.
Important limitations
The overall quality of evidence ranged from moderate to very low according to GRADE assessment. This summary relies on the supplied single-article abstract and metadata; the original paper is required for decision-grade interpretation of heterogeneity, study-specific limitations, and the clinical relevance of immunity blunting.
GIDS interpretation
This systematic review was identified through classifier links to measles, outbreak investigation, treatment, vaccination, and vaccine effectiveness topics. It provides synthesized evidence on early measles vaccination schedules that may inform immunization policy in outbreak-prone or high-transmission settings.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 12 auditable classifier relationships to diseases, places, topics, and study design.