Trial reportPLoS medicine2021
Efficacy of live attenuated and inactivated influenza vaccines among children in rural India: A 2-year, randomized, triple-blind, placebo-controlled trial.
Trial report in PLoS medicine, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
14 citing papers in PubMed, 3 syntheses or guidelines pooled it, 22 citations in OpenAlex.
- Comparison of 2 Doses vs 1 Dose in the First Season Children Are Vaccinated Against Influenza: A Systematic Review and Meta-Analysis.JAMA network open · 2025Pooled it
- Effectiveness of interventions to improve vaccine efficacy: a systematic review and meta-analysis.Systematic reviews · 2025Pooled it
- Head-to-head comparison of influenza vaccines in children: a systematic review and meta-analysis.Journal of translational medicine · 2024Pooled it
- Nasal shedding of vaccine viruses after immunization with a Russian-backbone live attenuated influenza vaccine in India.Influenza and other respiratory viruses · 2023Trial
- Age-dependent immune landscapes affect influenza vaccine effectiveness and guide precision strategies.Frontiers in immunology · 2026Review
- Influenza vaccination post-COVID-19 expands vaccine-specific effector CD4 T-cells and Tregs under positive influence of host trained innate immunity.NPJ vaccines · 2025Article
- Optimizing Influenza Vaccine Protection in India.Indian pediatrics · 2025Review
- Seasonality of Influenza and Optimizing Timing of Vaccination: Systematic Review and Meta-Analysis.Cureus · 2025Review
- Review
- Epidemic patterns of the different influenza virus types and subtypes/lineages for 10 years in Chongqing, China, 2010-2019.Human vaccines & immunotherapeutics · 2024Article
- Recent advances in the influenza virus vaccine landscape: a comprehensive overview of technologies and trials.Clinical microbiology reviews · 2024Review
- Respiratory viruses associated with severe acute respiratory infection in children aged <5 years at a tertiary care hospital in Delhi, India during 2013-15.Journal of global health · 2024Article
- Need for a robust public health response to seasonal influenza in India.The Indian journal of medical research · 2023Article
- Optimizing the Live Attenuated Influenza A Vaccine Backbone for High-Risk Patient Groups.Journal of virology · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
18 authors at 4 institutions in 2 countries.
Funding
Abstract
backgroundInfluenza is a cause of febrile acute respiratory infection (FARI) in India; however, few influenza vaccine trials have been conducted in India. We assessed absolute and relative efficacy of live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV) among children aged 2 to 10 years in rural India through a randomized, triple-blind, placebo-controlled trial conducted over 2 years. METHODS AND
findingsIn June 2015, children were randomly allocated to LAIV, IIV, intranasal placebo, or inactivated polio vaccine (IPV) in a 2:2:1:1 ratio. In June 2016, vaccination was repeated per original allocation. Overall, 3,041 children received LAIV (n = 1,015), IIV (n = 1,010), nasal placebo (n = 507), or IPV (n = 509). Mean age of children was 6.5 years with 20% aged 9 to 10 years. Through weekly home visits, nasal and throat swabs were collected from children with FARI and tested for influenza virus by polymerase chain reaction. The primary outcome was laboratory-confirmed influenza-associated FARI; vaccine efficacy (VE) was calculated using modified intention-to-treat (mITT) analysis by Cox proportional hazards model (PH) for each year. In Year 1, VE was 40.0% (95% confidence interval (CI) 25.2 to 51.9) for LAIV and 59.0% (95% CI 47.8 to 67.9) for IIV compared with controls; relative efficacy of LAIV compared with IIV was -46.2% (95% CI -88.9 to -13.1). In Year 2, VE was 51.9% (95% CI 42.0 to 60.1) for LAIV and 49.9% (95% CI 39.2 to 58.7) for IIV; relative efficacy of LAIV compared with IIV was 4.2% (95% CI -19.9 to 23.5). No serious adverse vaccine-attributable events were reported. Study limitations include differing dosage requirements for children between nasal and injectable vaccines (single dose of LAIV versus 2 doses of IIV) in Year 1 and the fact that immunogenicity studies were not conducted.
conclusionsIn this study, we found that LAIV and IIV vaccines were safe and moderately efficacious against influenza virus infection among Indian children.
trial registrationClinical Trials Registry of India CTRI/2015/06/005902.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.