Evidence map›Paper›PMID 36273491›Full record

Trial reportThe Lancet. Infectious diseases2023

Durability of ChAdOx1 nCoV-19 (AZD1222) vaccine and hybrid humoral immunity against variants including omicron BA.1 and BA.4 6 months after vaccination (COV005): a post-hoc analysis of a randomised, phase 1b-2a trial.

Shabir A Madhi, Gaurav Kwatra, Simone I Richardson, Anthonet L Koen, Vicky Baillie, Clare L Cutland, Lee Fairlie, Sherman D Padayachee, Keertan Dheda, Shaun L Barnabas and 27 more

Registry-linked trialOpen access · hybridAbstract readClinical Trial, Phase IClinical Trial, Phase IIRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in The Lancet. Infectious diseases, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04444674 (An Adaptive Phase I/II Randomized Placebo-controlled Trial to Determine Safety, Immunogenicity and Efficacy of Non-replicating ChAdOx1 SARS-CoV-2 Vaccine in South African Adults Living Without HIV; and Safety and Immunogenicity in Adults Living With HIV), which is not on this map. Cited by 19 papers.

0numbers the graph read from it
0cells of the map it votes in
19citing papers in PubMed
2.5field-weighted citation impact, top 9% of its field
1 · What the graph read from 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.

2 · The registry

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.

NCT04444674 phase1 / phase2unknown statusnot on this map

An Adaptive Phase I/II Randomized Placebo-controlled Trial to Determine Safety, Immunogenicity and Efficacy of Non-replicating ChAdOx1 SARS-CoV-2 Vaccine in South African Adults Living Without HIV; and Safety and Immunogenicity in Adults Living With HIV

TypeinterventionalSponsorUniversity of OxfordRan2020 to 2021Enrolled2,130ConditionsCoronavirusArmsChAdOx1 nCoV-19, Normal saline 0.9%
3 · Its place in the literature

Who cites it

19 citing papers in PubMed, 25 citations in OpenAlex.

  1. Article
  2. Hybrid Immunity in a Mozambican Cohort After 1 or 2 Doses of the BBIBP-CorV Vaccine.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2025
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  8. Tracking the COVID-19 vaccines: The global landscape.Human vaccines & immunotherapeutics · 2023
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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

37 authors at 9 institutions in 2 countries.

Shabir A MadhiSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. Electronic address: shabir.madhi@wits.ac.za.
Gaurav KwatraSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Simone I RichardsonSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Anthonet L KoenSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Vicky BaillieSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Clare L CutlandAfrican Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Lee FairlieWits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Sherman D PadayacheeSetshaba Research Centre, Tshwane, South Africa.
Keertan DhedaCentre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute, University of Cape Town, South Africa.
Shaun L BarnabasFamily Centre for Research with Ubuntu, Department of Paediatrics, Stellenbosch University, Cape Town, South Africa.
Qasim Ebrahim BhoratSoweto Clinical Trials Centre, Soweto, South Africa.
Carmen BrinerSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Khatija AhmedSetshaba Research Centre, Tshwane, South Africa; Faculty of Health Sciences, Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa.
Parvinder K AleyOxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK.
Sutika BhikhaSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
A E BhoratSoweto Clinical Trials Centre, Soweto, South Africa.
Aliasgar EsmailCentre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute, University of Cape Town, South Africa.
Elizea HorneWits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Haajira KaldineSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Christian K MukendiSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Vimbai Sharon MadzoreraSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Nelia P ManamelaSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Mduduzi MasilelaSetshaba Research Centre, Tshwane, South Africa.
S Tandile HermanusSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Thopisang MotlouSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Nonkululeko MzindleSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Suzette OelofseCentre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute, University of Cape Town, South Africa.
Faeezah PatelWits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Sarah RheadOxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK.
Lindie RossouwWits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Carol TaoushanisSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Samuel van EckWits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Teresa LambeDivision of Infection and Immunity, University College London, London, UK; Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK.
Sarah C GilbertDivision of Infection and Immunity, University College London, London, UK; Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK; Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
Andrew J PollardDivision of Infection and Immunity, University College London, London, UK; Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK.
Penny L MooreSouth African Medical Research Council Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa.
Alane IzuSouth African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
University of the Witwatersrand · ZASouth African Medical Research Council · ZAUniversity of Oxford · GBSetshaba Research Centre · ZAUniversity of Cape Town · ZANational Health Laboratory Service · ZASoweto CTC · ZAStellenbosch University · ZAUniversity College London · GB

Funding

Department of HealthGates Foundation INV-017710Medical Research Council MC_PC_19055
6 · The paper itself

Abstract

backgroundCOVID-19 vaccine rollout is lagging in Africa, where there has been a high rate of SARS-CoV-2 infection. We aimed to evaluate the effect of SARS-CoV-2 infection before vaccination with the ChAdOx-nCoV19 (AZD1222) vaccine on antibody responses through to 180 days.

methodsWe did an unmasked post-hoc immunogenicity analysis after the first and second doses of AZD1222 in a randomised, placebo-controlled, phase 1b-2a study done in seven locations in South Africa. AZD1222 recipients who were HIV-uninfected, were stratified into baseline seropositive or seronegative groups using the serum anti-nucleocapsid (anti-N) immunoglobulin G (IgG) electroluminescence immunoassay to establish SARS-CoV-2 infection before the first dose of AZD1222. Binding IgG to spike (anti-S) and receptor binding domain (anti-RBD) were measured before the first dose (day 0), second dose (day 28), day 42, and day 180. Neutralising antibody (NAb) against SARS-CoV-2 variants D614G, beta, delta, gamma, and A.VOI.V2, and omicron BA1 and BA.4 variants, were measured by pseudovirus assay (day 28, day 42, and day 180). This trial is registered with ClinicalTrials.gov, NCT04444674, and the Pan African Clinicals Trials Registry, PACTR202006922165132.

findingsOf 185 individuals who were randomly assigned to AZD1222, we included 91 individuals who were baseline seropositive and 58 who were baseline seronegative, in the final analysis. In the seropositive group, there was little change of anti-S IgG (and anti-RBD IgG) or neutralising antibody (NAb) titres at day 42 compared with at day 28. Anti-S (and anti-RBD) IgG geometric mean concentrations (GMCs) were higher throughout in the seropositive compared with the seronegative group, including at day 180 (GMCs 517·8 [95% CI 411·3-651·9] vs 82·1 [55·2-122·3] BAU/mL). Also D614G NAb geometric mean titres (GMTs) were higher in the seropositive group than the seronegative group, as was the percentage with titres of at least 185 (80% putative risk reduction threshold [PRRT] against wild-type-alpha COVID-19), including at day 180 (92·0% [74·0-99·0] vs 18·2% [2·3-51·8). Similar findings were observed for beta, A.VOI.V2, and gamma. For delta, BA.1, and BA.4, NAb GMTs and the proportion with titres above the PRRT were substantially higher in the seropositive compared with seronegative group at day 28 and day 42, but no longer differed between the groups by day 180.

interpretationA single dose of AZD1222 in the general African population, where COVID-19 vaccine coverage is low and SARS-CoV-2 seropositivity is 90%, could enhance the magnitude and quality of antibody responses to SARS-CoV-2.

fundingThe Bill & Melinda Gates Foundation, the South African Medical Research Council, the UK Research and Innovation, the UK National Institute for Health Research, and the South African Medical Research Council. TRANSLATION: For the Zulu translation of the abstract see Supplementary Materials section.

Indexed as

COVID-19VaccinesAntibodies, NeutralizingAntibodies, ViralChAdOx1 nCoV-19COVID-19 VaccinesHumansImmunity, HumoralImmunogenicity, VaccineImmunoglobulin GSARS-CoV-2South AfricaVaccinationAntibodies, NeutralizingAntibodies, ViralChAdOx1 nCoV-19COVID-19 VaccinesImmunoglobulin GVaccines

Identifiers

PMID36273491
PMCPMC9584570
OpenAlexW4306907012

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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.