The Journal of infectious diseases
October 15, 2026 · via Europe PMC
Rapid Differentiation of Vaccine and Wild-Type Measles Virus During an Ongoing Outbreak using a new molecular assay.
Bucris E, Levin T, Azar R, +8 more, Erster O
AI summary — for doctors, generated from the abstract only
A new two-step RT-qPCR assay quickly told vaccine from wild-type measles virus with 100% accuracy against sequencing and was used during the 2025-2026 outbreak in Israel.
What was studied
Development and implementation of a differential measles RT-qPCR: a first step (MRRV) distinguishing rubella, wild-type and vaccine measles, and a second step separating genotypes A (vaccine), B and D, compared with N gene sequencing.
Key findings
- The assay detects 10-50 copies per reaction and classified weak samples (Cq > 32) with 100% accuracy versus sequencing
- Over 4,000 clinical samples were evaluated, and about 9% of those tested in the outbreak came from the vaccine strain
- Municipalities running active vaccination campaigns had more vaccine-strain detections (more than 10 cases each) than those with routine vaccination (1-2 cases); the assay also identified double infections
Clinical relevance
Could let public health teams rapidly avoid misclassifying vaccine-related positives as outbreak cases, and is cheaper and faster than sequencing.
Who should care
Limitations
The abstract does not detail sample selection or specificity numbers beyond the sequencing comparison, and the assay targets a limited set of genotypes.
A rapid, accurate assay for separating vaccine and wild-type measles that supports outbreak response.
This is an AI-generated summary of the published abstract, not a clinical recommendation. It may not reflect the full text or subsequent updates — verify against the original source before acting on it.
Abstract
BACKGROUND
Differentiating wild and vaccine measles virus (MeV) strains is critical for appropriate healthcare response during outbreak vaccination campaigns. Sequencing, the current standard, is expensive, time-consuming, and limited to specialized laboratories. We developed and implemented a novel differential MeV RT-qPCR assay to address these challenges, which we describe herein.
METHODS
We designed a differential two-step assay; the first step, termed MRRV, distinguishes between rubella, wild MeV, and vaccine MeV. The second, termed "MeV differential", differentiates between genotypes A (vaccine), B and D.
RESULTS
The assay detects 10-50 copies per reaction and accurately classifies weak clinical samples (Cq > 32), with 100% accuracy, compared with the N gene sequencing gold standard. Evaluated on over 4,000 clinical samples retrospectively and during the 2025-2026MeV outbreak in Israel, the assay revealed that ∼9% of tested originated from vaccine strain. Among tested municipalities, those running active vaccination campaigns had significantly higher vaccine strain detections (>10 cases each) than those with routine vaccination (1-2 cases). Retrospective analysis of samples from 2018-2024 identified a mix of B and D strains. The novel assay successfully identified double infection cases (exposure to a wild strain shortly before or after vaccination).
CONCLUSION
The novel assay proved useful both as a diagnostic tool that enables focused, efficient healthcare response, and as an epidemiological tool that provides valuable information in real-time. This assay is faster, cheaper and more amendable for high throughput testing, compared with the gold-standard sequencing classification.
DOI
10.1093/infdis/jiag518
PMID
42879187
Research metadata (titles, abstracts, authors, publication dates) is sourced from Europe PMC, which aggregates content from PubMed/MEDLINE, PubMed Central, and other providers under the U.S. National Library of Medicine (NLM/NCBI). NLM does not claim copyright on abstracts; the original journal publishers or authors may hold rights to the full articles. AI-generated summaries are derived only from the abstract, never the full text, and are always labeled as AI-generated.
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