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Sisonke 2 - A COVID-19 Vaccine Boost Open Label Study.

Open-label, Single-arm Phase 3B Implementation Study to Evaluate the Effectiveness of the Homologous Boost of Ad26.COV2.S COVID-19 Vaccine Following the Prime Dose Among Sisonke Participants in South Africa(VAC31518COV30XX)

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05148845
Acronym
Sisonke Boost
Enrollment
500000
Registered
2021-12-08
Start date
2021-11-10
Completion date
2023-06-30
Last updated
2026-09-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

SARS CoV 2 Infection

Brief summary

To evaluate the effectiveness of the single dose Ad26.COV2.S COVID-19 vaccine plus a homologous boostwith Ad26.COV2.S COVID-19 vaccine among Sisonke participants as compared to unboosted Sisonkeparticipants; vaccinated; and unvaccinated populations in South Africa

Detailed description

Purpose To evaluate the effectiveness and safety of the single dose Ad26.COV2.S (Jansen) COVID-19 vaccine plus a homologous boost with Ad26.COV2.S (Janssen) COVID-19 vaccine among Sisonke participants as compared to unboosted Sisonke participants In addition the investigators will continue to evaluate VE of the Sisonke Boost compared to: i) Vaccinated populations pre boosts ii) Unvaccinated populations in South Africa. Study design Open-label, single-arm phase 3B vaccine implementation study Rationale South Africa is severely affected by the global COVID-19 epidemic, and following the initial prime vaccination among HCWs in the first 4 months of 2021. New data has demonstrated the safety and effectiveness of a booster dose given two months or more after the initial Ad26.COV2.S. This provides the rationale and feasibility for the evaluation of a homologous booster vaccine dose to the cohort of vaccinated Sisonke participants to inform the larger vaccine rollout. Study participants Sisonke participants age 18 and over working in the South African public and private health care sector (approx N=500 000) who were enrolled in Sisonke and have not subsequently had a further booster vaccine dose. Study sites Department of Health Vaccine Administration Sites across South Africa supported by the Sisonke (Together) (VAC31518COV3012) Trial Research Site Investigators and Study Staff Study duration Participants will receive a homologous Ad26.COV2.S (Janssen) booster dose of vaccine at least 6 months post the prime vaccination. The investigators will monitor outcomes utilising the DATCOV surveillance system and NHLS/NICD SARS COV-2 testing databases for up to 2 years post initial vaccination. Study products Ad26.COV2.S by Janssen administered as a single dose followed by a single booster injection. Primary objectives • To assess the effectiveness of Ad26.COV2.S vaccine as a homologous boost on severe COVID, hospitalizations and deaths in Sisonke participants as compared with the unboosted Sisonke populations. Secondary objectives To assess the effectiveness of Ad26.COV2.S vaccine as a homologous boost on severe COVID, hospitalizations and deaths in Sisonke participants as compared vaccinated and unvaccinated populations of essential workers in South Africa. * To estimate the incidence of symptomatic SARS CoV-2 infections in Sisonke participants following a boost compared with the unboosted Sisonke populations and general vaccinated and unvaccinated population in South Africa * To estimate booster dose uptake among Sisonke participants in South Africa * To monitor the genetic diversity of breakthrough SARS CoV-2 infections. * To monitor safety in the case of homologous boosts in Sisonke participants.

Interventions

BIOLOGICALSisonke Heterologous mRNA-1273 boost after prime with Ad26.COV2.S

To evaluate the effectiveness and safety of the single dose Ad26.COV2.S (Jansen) COVID-19 vaccine plus a homologous boost with Ad26.COV2.S (Janssen) COVID-19 vaccine among Sisonke participants as compared to unboosted Sisonke participants In addition we will continue to evaluate VE of the Sisonke Boost compared to: i) Vaccinated populations pre boosts ii) Unvaccinated populations in South Africa.

Sponsors

Wits Health Consortium (Pty) Ltd
Lead SponsorOTHER
National Department of Health of South Africa
CollaboratorUNKNOWN
National Institute of Communicable Diseases - NICD
CollaboratorUNKNOWN
KwaZulu-Natal Research Innovation and Sequencing Platform - KRISP
CollaboratorUNKNOWN
Fred Hutchinson Cancer Center
CollaboratorOTHER
Hutchinson Center Research Institute of South Africa (HCRISA)
CollaboratorUNKNOWN
Janssen Vaccines & Prevention B.V.
CollaboratorINDUSTRY
Bio Analytical Research Corporation
CollaboratorINDUSTRY
Dis-Chem Pharmacy
CollaboratorUNKNOWN
BioVac
CollaboratorUNKNOWN
Biocair
CollaboratorUNKNOWN
Right to Care
CollaboratorOTHER
Clinical Laboratory Services
CollaboratorOTHER
Institute of Infectious Disease and Molecular Medicine
CollaboratorUNKNOWN

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE

Intervention model description

Open-label, single-arm phase 3B vaccine implementation study

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Age 18 and older * All Sisonke participants * Received a priming Ad26.SARS.COV.2.S vaccination as part of the Sisonke study at least 6 months prior * Participants who are pregnant or report breastfeeding at the time of enrolment may be included. * Willingness and ability to comply with vaccination plan and other study procedures. * Capable of giving electronic or personal signed informed consent as described in Appendix 5, which includes compliance with the requirements in this protocol.

Exclusion criteria

* Participants who have received boosting vaccination through other means. * Any significant acute or chronic medical condition, situation or circumstance that in the opinion of the PI/designee makes the participant unsuitable for participation in the study, or jeopardises the safety or rights of the participant * Current participation in any other research studies that would interfere with the objectives of this study. The determination of whether participation in another study would be exclusionary for a given participant will be made by the PI/designee. * Participants with a history of heparin-induced thrombocytopenia or TTS

Design outcomes

Primary

MeasureTime frameDescription
To assess the effectiveness of Ad26.COV2.S (Janssen) boost vaccine on severe COVID, hospitalizations and deaths in Sisonke participants as compared to unboosted Sisonke participants (single Ad26 vaccine only)24 MonthsRates of hospitalizations and deaths among boosted Sisonke participants versus unboosted Sisonke participants and unvaccinated populations in South Africa

Secondary

MeasureTime frameDescription
To assess the effectiveness of Ad26.COV2.S (Janssen) boost vaccine on severe COVID, hospitalizations and deaths in Sisonke participants as compared to the vaccinated and unvaccinated populations (no vaccination) in South Africa.24 MonthsRates of hospitalizations and deaths among boosted Sisonke participants versus unboosted vaccinated and unvaccinated populations in South Africa
To estimate the incidence of symptomatic SARS CoV-2 infections among boosted Sisonke ppts.24 monthsIncidence rate of SARS CoV-2 infection as indicated by self-report and validation in national laboratory records. Rates of severe disease in Sisonke participants who are found to be RT-PCR positive at any time up to 2 years post prime vaccination
To monitor the genetic diversity of breakthrough SARS CoV-2 infections24 MonthsGenetic diversity of breakthrough infection virus as determined by whole genome sequencing. This will be recovered from national laboratories.
To estimate booster vaccine uptake among Sisonke participants in South Africa24 MonthsProportion of Sisonke participants approached for study participation taking part in the boost study and receiving the booster vaccine
To monitor safety in homologous boosts24 MonthsAll SAEs and events of special interest will be collected and reported.

Countries

South Africa

Contacts

PRINCIPAL_INVESTIGATORGlenda Gray, MBChB

Non-Executive Director

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 2, 2026