ArticleNature communications2022
Vaccine effectiveness of CoronaVac against COVID-19 among children in Brazil during the Omicron period.
Article in Nature communications, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers, 5 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
41 citing papers in PubMed, 5 syntheses or guidelines pooled it, 53 citations in OpenAlex.
- The effect of COVID-19 vaccine to the Omicron variant in children and adolescents: a systematic review and meta-analysis.Frontiers in public health · 2024Pooled it
- Effectiveness of COVID-19 vaccines among children and adolescents against SARS-CoV-2 variants: a meta-analysis.European journal of pediatrics · 2023Pooled it
- Immunogenicity, effectiveness, and safety of COVID-19 vaccines among children and adolescents aged 2-18 years: an updated systematic review and meta-analysis.World journal of pediatrics : WJP · 2023Pooled it
- Effectiveness of homologous or heterologous immunization regimens against SARS-CoV-2 after two doses of inactivated COVID-19 vaccine: A systematic review and meta-analysis.Human vaccines & immunotherapeutics · 2023Pooled it
- Real-world effectiveness and factors associated with effectiveness of inactivated SARS-CoV-2 vaccines: a systematic review and meta-regression analysis.BMC medicine · 2023Pooled it
- Immunogenicity and safety of CoronaVac vaccine in children and adolescents (Immunita-002, Brazil): A phase IV six-month follow up.Scientific reports · 2025Trial
- Efficacy, immunogenicity and safety of CoronaVac® in children and adolescents aged 6 months to 17 years: a multicenter, randomized, double-blind, placebo-controlled phase III clinical trial.Nature communications · 2024Trial
- Effect of an inactivated coronavirus disease 2019 vaccine, CoronaVac, on blood coagulation and glucose: a randomized, controlled, open-label phase IV clinical trial.Frontiers in immunology · 2023Trial
- Risk Factors of COVID-19 Severity and Related Death in Children in the Post-Pandemic Era.Microorganisms · 2026Article
- Effectiveness of COVID-19 Vaccine Boosters in Children Across Pandemic and Endemic Periods.Microorganisms · 2026Article
- Effectiveness of COVID-19 Vaccines Against Hospitalization and Severe Disease in Children with Diabetes Mellitus During Pandemic and Post-Pandemic Eras.Microorganisms · 2026Article
- Real-world effectiveness and causal mediation study of BNT162b2 on long COVID risks in children and adolescents.EClinicalMedicine · 2025Article
- Effectiveness of HPV vaccine as part of national immunization program for preventing HPV infection in Thai schoolgirls after seven years post-vaccination.Human vaccines & immunotherapeutics · 2024Article
- Effectiveness of inactivated COVID-19 vaccines in preventing COVID-19-related hospitalization during the Omicron BF.7-predominant epidemic wave in Beijing, China: a cohort study.BMC infectious diseases · 2024Article
- Impact of COVID-19 Vaccination on Mortality and Clinical Outcomes in Hemodialysis Patients.Vaccines · 2024Article
- Real-world effectiveness of the heterologous SOBERANA-02 and SOBERANA-Plus vaccine scheme in 2-11 years-old children during the SARS-CoV-2 Omicron wave in Cuba: a longitudinal case-population study.Lancet regional health. Americas · 2024Article
- Transmission risks of Omicron BA.5 following inactivated COVID-19 vaccines among children and adolescents in China.Communications medicine · 2024Article
- Real-World Effectiveness of BNT162b2 Against Infection and Severe Diseases in Children and Adolescents.Annals of internal medicine · 2024Observational
- Article
- Immunogenicity of the CoronaVac vaccine in children: a real-world study.Frontiers in immunology · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
14 authors at 6 institutions in 2 countries.
Funding
Abstract
Although severe COVID-19 in children is rare, they may develop multisystem inflammatory syndrome, long-COVID and downstream effects of COVID-19, including social isolation and disruption of education. Data on the effectiveness of the CoronaVac vaccine is scarce during the Omicron period. In Brazil, children between 6 to 11 years are eligible to receive the CoronaVac vaccine. We conducted a test-negative design to estimate vaccine effectiveness using 197,958 tests from January 21, 2022, to April 15, 2022, during the Omicron dominant period in Brazil among children aged 6 to 11 years. The estimated vaccine effectiveness for symptomatic infection was 39.8% (95% CI 33.7-45.4) at ≥14 days post-second dose. For hospital admission vaccine effectiveness was 59.2% (95% CI 11.3-84.5) at ≥14 days. Two doses of CoronaVac in children during the Omicron period showed low levels of protection against symptomatic infection, and modest levels against severe illness.
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Registered trials
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.