ArticleBMJ (Clinical research ed.)2021
Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of covid-19 in Brazil: test negative case-control study.
Article in BMJ (Clinical research ed.), 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. It is linked to 2 registered trials, which are not on this map. Cited by 201 papers, 9 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.
A Multicenter, Randomized, Double Blind, Controlled, Phase III Clinical Trial (Immunobridging Study) of Vaksin Merah Putih - UA SARS-CoV-2 (Vero Cell Inactivated) in Healthy Population Aged 18 Years and Above
An Open Label, Phase III Clinical Trial (Immunobridging Study) of INAVAC (Vaksin Merah Putih - UA-SARS CoV-2 (Vero Cell Inactivated)) in Healthy Population Aged 12 to 17 Years Old
Who cites it
201 citing papers in PubMed, 9 syntheses or guidelines pooled it.
- Prior infections and effectiveness of SARS-CoV-2 vaccine in test-negative studies: a systematic review and meta-analysis.American journal of epidemiology · 2024Pooled it
- Clinical Severity of SARS-CoV-2 Variants during COVID-19 Vaccination: A Systematic Review and Meta-Analysis.Viruses · 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
- Effectiveness of COVID-19 vaccines against SARS-CoV-2 variants of concern: a systematic review and meta-analysis.BMC medicine · 2022Pooled it
- The relationship between COVID-19 viral load and disease severity: A systematic review.Immunity, inflammation and disease · 2022Pooled it
- Real-Word Effectiveness of Global COVID-19 Vaccines Against SARS-CoV-2 Variants: A Systematic Review and Meta-Analysis.Frontiers in medicine · 2022Pooled it
- Effectiveness and Cost-Effectiveness of Inactivated Vaccine to Address COVID-19 Pandemic in China: Evidence From Randomized Control Trials and Real-World Studies.Frontiers in public health · 2022Pooled it
- Real-world effectiveness of COVID-19 vaccines: a literature review and meta-analysis.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2022Pooled it
- Gam-COVID-Vac, EpiVacCorona, and CoviVac effectiveness against lung injury during Delta and Omicron variant surges in St. Petersburg, Russia: a test-negative case-control study.Respiratory research · 2022Trial
- Safety and immunogenicity of a live-attenuated influenza virus vector-based intranasal SARS-CoV-2 vaccine in adults: randomised, double-blind, placebo-controlled, phase 1 and 2 trials.The Lancet. Respiratory medicine · 2022Trial
- Immunogenicity and safety of a third dose of CoronaVac, and immune persistence of a two-dose schedule, in healthy adults: interim results from two single-centre, double-blind, randomised, placebo-controlled phase 2 clinical trials.The Lancet. Infectious diseases · 2022Trial
- Heterologous versus homologous COVID-19 booster vaccination in previous recipients of two doses of CoronaVac COVID-19 vaccine in Brazil (RHH-001): a phase 4, non-inferiority, single blind, randomised study.Lancet (London, England) · 2022Trial
- Humoral and cellular immune responses to CoronaVac up to one year after vaccination.Frontiers in immunology · 2022Trial
- Immunogenicity, Effectiveness, and Safety of Inactivated Virus (CoronaVac) Vaccine in a Two-Dose Primary Protocol and BNT162b2 Heterologous Booster in Brazil (Immunita-001): A One Year Period Follow Up Phase 4 Study.Frontiers in immunology · 2022Trial
- Recognition of Variants of Concern by Antibodies and T Cells Induced by a SARS-CoV-2 Inactivated Vaccine.Frontiers in immunology · 2021Trial
- The effectiveness of COVID-19 vaccines and the added benefit of booster doses in Hessen, Germany, during the COVID-19 pandemic: Results from a vaccinated-only study.Human vaccines & immunotherapeutics · 2026Article
- Rational design of next-generation vaccine adjuvants: From molecular mechanisms to hybrid delivery platforms.Human vaccines & immunotherapeutics · 2026Review
- Article
- Effectiveness, Safety, and Immunogenicity of a Second COVID-19 Vaccine Booster in the Elderly: A Systematic Review and Meta-Analysis Protocol.Health science reports · 2026Article
141 more citing papers are in PubMed but not listed here.
Corrections and comments
- Erratum issued
Authors and funding
20 authors.
Funding
Abstract
objectiveTo estimate the effectiveness of the inactivated whole virus vaccine, CoronaVac (Sinovac Biotech), against symptomatic covid-19 in the elderly population of São Paulo state, Brazil during widespread circulation of the gamma variant.
designTest negative case-control study.
settingCommunity testing for covid-19 in São Paulo state, Brazil.
participants43 774 adults aged ≥70 years who were residents of São Paulo state and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 29 April 2021. 26 433 cases with symptomatic covid-19 and 17 622 test negative controls with covid-19 symptoms were formed into 13 283 matched sets, one case with to up to five controls, according to age, sex, self-reported race, municipality of residence, previous covid-19 status, and date of RT-PCR test (±3 days).
interventionVaccination with a two dose regimen of CoronaVac.
main outcome measuresRT-PCR confirmed symptomatic covid-19 and associated hospital admissions and deaths.
resultsAdjusted vaccine effectiveness against symptomatic covid-19 was 24.7% (95% confidence interval 14.7% to 33.4%) at 0-13 days and 46.8% (38.7% to 53.8%) at ≥14 days after the second dose. Adjusted vaccine effectiveness against hospital admissions was 55.5% (46.5% to 62.9%) and against deaths was 61.2% (48.9% to 70.5%) at ≥14 days after the second dose. Vaccine effectiveness ≥14 days after the second dose was highest for the youngest age group (70-74 years)-59.0% (43.7% to 70.2%) against symptomatic disease, 77.6% (62.5% to 86.7%) against hospital admissions, and 83.9% (59.2% to 93.7%) against deaths-and declined with increasing age.
conclusionsVaccination with CoronaVac was associated with a reduction in symptomatic covid-19, hospital admissions, and deaths in adults aged ≥70 years in a setting with extensive transmission of the gamma variant. Vaccine protection was, however, low until completion of the two dose regimen, and vaccine effectiveness was observe to decline with increasing age among this elderly population.
Indexed as
Identifiers
What OpenQuestion holds
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.