ArticleWellcome open research2023
Effectiveness of BNT162b2 and ChAdOx1 against SARS-CoV-2 household transmission: a prospective cohort study in England.
Article in Wellcome open research, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 19 papers, 2 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
19 citing papers in PubMed, 2 syntheses or guidelines pooled it, 18 citations in OpenAlex.
- SARS-CoV-2 variants of concern in children and adolescents with COVID-19: a systematic review.BMJ open · 2023Pooled it
- Household Secondary Attack Rates of SARS-CoV-2 by Variant and Vaccination Status: An Updated Systematic Review and Meta-analysis.JAMA network open · 2022Pooled it
- Recombinant Bacillus subtilis spores expressing SARS-CoV-2 spike protein induced humoral, mucosal, and cellular immunity in mice.Scientific reports · 2025Article
- The effect of COVID-19 vaccination on change in contact and implications for transmission.Epidemics · 2025Article
- Natural, vaccine-induced immunity and the probability of experiencing SARS-CoV-2 infection in a household cohort in Rio de Janeiro.Scientific reports · 2025Article
- Tracking vaccine effectiveness in an evolving pandemic, countering misleading hot takes and epidemiologic fallacies.American journal of epidemiology · 2025Article
- How do large-scale population studies inform vaccine evaluations in England?Clinical and experimental immunology · 2025Review
- Household transmission of SARS-CoV-2 in five US jurisdictions: Comparison of Delta and Omicron variants.PloS one · 2025Article
- Methodology of comparative studies on the relative effectiveness of COVID-19 vaccines: a systematic review.Osong public health and research perspectives · 2024Article
- Mucosal immunization with ChAd-SARS-CoV-2-S prevents sequential transmission of SARS-CoV-2 to unvaccinated hamsters.Science advances · 2024Article
- Article
- Retrospective, Observational Studies for Estimating Vaccine Effects on the Secondary Attack Rate of SARS-CoV-2.American journal of epidemiology · 2023Observational
- Effectiveness of BNT162b2 and ChAdOx1 against SARS-CoV-2 household transmission: a prospective cohort study in England.Wellcome open research · 2023Article
- Association Between Population-Level Factors and Household Secondary Attack Rate of SARS-CoV-2: A Systematic Review and Meta-analysis.Open forum infectious diseases · 2023Article
- Epidemiological impact and cost-effectiveness analysis of COVID-19 vaccination in Kenya.BMJ global health · 2022Article
- Effect of vaccination on household transmission of SARS-CoV-2 Delta variant of concern.Nature communications · 2022Article
- SARS-CoV-2: from herd immunity to hybrid immunity.Nature reviews. Immunology · 2022Article
- Article
- Household secondary attack rates of SARS-CoV-2 by variant and vaccination status: an updated systematic review and meta-analysis.medRxiv : the preprint server for health sciences · 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
12 authors at 2 institutions in 1 country.
Funding
Abstract
Background: The ability of SARS-CoV-2 vaccines to protect against infection and onward transmission determines whether immunisation can control global circulation. We estimated the effectiveness of Pfizer-BioNTech mRNA vaccine (BNT162b2) and Oxford AstraZeneca adenovirus vector vaccine (ChAdOx1) vaccines against acquisition and transmission of the Alpha and Delta variants in a prospective household study in England. Methods: Households were recruited based on adult purported index cases testing positive after reverse transcription-quantitative (RT-q)PCR testing of oral-nasal swabs. Purported index cases and their household contacts took oral-nasal swabs on days 1, 3 and 7 after enrolment and a subset of the PCR-positive swabs underwent genomic sequencing conducted on a subset. We used Bayesian logistic regression to infer vaccine effectiveness against acquisition and transmission, adjusted for age, vaccination history and variant. Results: Between 2 February 2021 and 10 September 2021, 213 index cases and 312 contacts were followed up. After excluding households lacking genomic proximity (N=2) or with unlikely serial intervals (N=16), 195 households with 278 contacts remained, of whom 113 (41%) became PCR positive. Delta lineages had 1.53 times the risk (95% Credible Interval: 1.04 - 2.20) of transmission than Alpha; contacts older than 18 years old were 1.48 (1.20 - 1.91) and 1.02 (0.93 - 1.16) times more likely to acquire an Alpha or Delta infection than children. Effectiveness of two doses of BNT162b2 against transmission of Delta was 36% (-1%, 66%) and 49% (18%, 73%) for ChAdOx1, similar to their effectiveness for Alpha. Protection against infection with Alpha was higher than for Delta, 69% (9%, 95%) Conclusions: BNT162b2 and ChAdOx1 reduce transmission of the Delta variant from breakthrough infections in the household setting, although their protection against infection within this setting is low.
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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.