ArticleVaccine2022
Impact of prior vaccination with Covishield
Article in Vaccine, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 21 papers, 1 of them a synthesis that pooled it.
What it found
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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.
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Who cites it
21 citing papers in PubMed, 1 synthesis or guideline pooled it, 28 citations in OpenAlex.
- Inactivated vaccine Covaxin/BBV152: A systematic review.Frontiers in immunology · 2022Pooled it
- Time-to-event analysis of COVID-19 precautionary dose vaccination among healthcare workers in a teaching institute of a metropolitan city in India, using Co-WIN data.Journal of family medicine and primary care · 2025Article
- Risk of COVID-19 infection among frontline healthcare workers during the COVID-19 pandemic.World journal of virology · 2025Article
- Assessing breakthrough infections: Covishield (late schedule) versus Covaxin - A prospective comparative analysis in the general population.Journal of family medicine and primary care · 2025Article
- Immunological memory in infected & exposure näive individuals one year post SARS-CoV-2 vaccination.The Indian journal of medical research · 2025Article
- Comparative Analysis of COVID-19 Severity and Mortality Among Vaccinated and Unvaccinated Individuals During the Delta Variant Surge in a Tertiary Care Center: A Cohort Study.Health science reports · 2025Article
- Clinical profile of COVID-19 among vaccinated and non-vaccinated patients in India.Bioinformation · 2025Article
- Mortality and potential years of life lost due to COVID-19 among healthcare workers in Bahia, 2020-2022.Epidemiologia e servicos de saude : revista do Sistema Unico de Saude do Brasil · 2025Article
- The Influence of SARS-CoV-2 Vaccination on the Mortality and Outcomes of Patients with Both Myocardial Infarction and COVID-19.Vaccines · 2024Article
- Adverse events following Covaxin administration among adolescents (15-18 years) - A pharmacovigilance study in a district in Northern India.Journal of family medicine and primary care · 2024Article
- Factors for hesitancy towards vaccination against COVID-19 among the adult population in Puducherry, India - a cross sectional study.BMC public health · 2023Article
- A survey on Malaysian's acceptance and perceptions towards COVID-19 booster dose.Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society · 2023Article
- Antibody titres in fully vaccinated healthcare workers with and without breakthrough infection during the Delta and Omicron waves.Journal of family medicine and primary care · 2023Article
- The dynamics of SARS-CoV-2 infection in unvaccinated and vaccinated populations in Mumbai, India, between 28 December 2020 and 30 August 2021.Archives of virology · 2023Article
- Article
- The Relationship of COVID-19 Vaccination with Mortality Among 86,732 Hospitalized Patients: Subpopulations, Patient Factors, and Changes over Time.Journal of general internal medicine · 2023Article
- Durability of ChAdOx1 nCoV-19 (CovishieldVaccines · 2022Article
- Clinico-pathological study among COVID-19 patients during the second wave of COVID-19 pandemic in Andaman Nicobar Island- "A retrospective cross-sectional study".Journal of family medicine and primary care · 2022Article
- Demographics and Clinical Characteristics of COVID-19-vaccinated Patients Admitted to ICU: A Multicenter Cohort Study from India (PostCoVac Study-COVID Group).Indian journal of critical care medicine : peer-reviewed, official publication of Indian Society of Critical Care Medicine · 2022Article
- Reduced Risk of Progression from Non-Severe to Severe COVID-19 in Hospitalized Dialysis Patients by Full COVID-19 Vaccination.Journal of clinical medicine · 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
23 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundCOVID-19 vaccines were authorised for emergency use to mitigate the impact of the pandemic. This study evaluated the effect of prior vaccination with either Oxford Astra Zeneca's Covishield™ or Bharath Biotech's Covaxin® on mortality among symptomatic COVID-19 patients during the second wave of the pandemic in India. METHODOLOGY: In this cohort study comprising of RT-PCR confirmed symptomatic COVID-19 patients presenting during April and May 2021, the effect of prior vaccination on mortality (primary outcome), need for hospitalization, oxygen therapy, non-invasive ventilation (NIV) and intensive care unit (ICU) admission were assessed and expressed as risk ratio (RR) with 95% confidence intervals (CI).
resultsThe mean (SD) age of the cohort (n = 4183) was 46.3 (15.5) years; 17.9% (748/4183) had received at least one dose of Covishield™ and 4.8% (201/4183) had received Covaxin®. Mortality was 0.2% (95% CI: 0.2% - 0.7%), 3.5% (1.9-5.2%), 6.2% (0.3-12%) and 12.9% (11.8-14.1%) among fully vaccinated (>2 weeks after two doses), partially vaccinated (>2 weeks after one dose or <2 weeks after two doses), indeterminate (<2 weeks after one dose) and unvaccinated patients respectively. The difference in mortality among unvaccinated vs. fully vaccinated was 12.7% (95% CI: 11.4-13.9%), unvaccinated vs. partially vaccinated was 9.4% (7.4-11.4%) and unvaccinated vs. indeterminate vaccinated was 6.8% (0.8-12.7%). On adjusted analysis, as compared to unvaccinated patients, at least one dose of vaccine reduced the need for hospitalization (RR: 0.40; 95% CI: 0.35-0.47), oxygen (0.33; 0.27-0.40), NIV (0.23; 0.17-0.32), ICU admission (0.18; 0.12-0.27) and mortality (0.18; 0.11-0.29).
conclusionAmong symptomatic COVID-19 patients, prior vaccination with Covishield ™ or Covaxin® impacted the severity of illness and reduced mortality during a period of widespread delta variant circulation. Full vaccination conferred greater protection than partial vaccination.
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