Study to Evaluate the Immunogenicity and Safety of Heterologous SARS-CoV-2 Vaccine Schemes

Randomised Phase II Study to Evaluate the Immunogenicity and Safety of Heterologous SARS-CoV-2 Vaccine Schemes (rAd26-rAd5, ChAdOx1 nCoV-19 and BBIBP-CorV).

To determine whether a heterologous vaccination regimen in individuals with no known previous history of COVID-19 is non-inferior to that observed with counterpart regimens currently in use in Argentina.

Study Overview

• Status: Completed
• Conditions: COVID-19 Vaccines
• Intervention / Treatment: Drug: Gam-COVID-Vac / Gam-COVID-Vac

Detailed Description

The Covid-19 disease caused by the SARS-COV 2 virus has caused a pandemic with more than 180 million cases worldwide and more than 4 million deaths. In Argentina, this pandemic has had a significant impact, with about 4.5 million cases and about 95,000 deaths. In no more than nine months, medical science developed different vaccines to prevent new cases and mitigate this pandemic.

At the time of the presentation of this research protocol, there are four vaccines for the prevention of COVID-19 approved for emergency use by the National Administration of Medicines, Food and Medical Technology (ANMAT). Of these, three (1-3) are currently available and are part of the vaccination campaign. Of these three vaccines, two use a non-replicating viral vector platform (Gam-COVID-Vac and ChAdOx1 nCoV-19) while one uses an inactivated virus platform (BBIBP-CorV). All require the administration of two doses with an administration interval of at least 21 days.

All these vaccines were designed to be used with a homologous two-dose regimen. However, for both logistical and biomedical reasons, the need to use vaccines in heterologous regimens (one dose of one vaccine and a second dose of another vaccine) is emerging worldwide. The efficacy and safety of this type of regimen has not yet been demonstrated.

In Argentina, there are a large number of people who currently have one dose of Gam-COVID-Vac vaccine and who - even after a period of ≥21 days - have not received the second component. At the same time, the provision of the second component of the Gam-COVID-Vac vaccine is delayed due to production and distribution logistics.

As of June 2021, among the universe of people vaccinated with Gam-COVID, residents of CABA, vaccinated in establishments in the City of Buenos Aires - and excluding deceased and infected people - there were a total of 325,788 people with one dose and ≥22 and ≤90 days since the first dose was administered. In a context of high viral circulation, it is desirable to try to vaccinate as much of the population as possible with a full schedule in the shortest possible time. In addition, new variants of SARS-COV2 virus possessing the E384K genomic variant such as the gamma strain (formerly Manaus), the beta strain (known as South African) and the Delta strain (also known as Indian) have the ability to evade the immune system and therefore most laboratories that have developed vaccines recognise that the efficacy of the vaccines requires two doses.

The use of heterologous schedules is a source of active research in various parts of the world (4-6). However, most of this research is testing the combination of a combination schedule that includes an mRNA vaccine. There is an ongoing study sponsored by the Gamaleya Institute and AstraZeneca that is evaluating the immunogenicity of a scheme similar to the one proposed in this trial. Results from this joint trial would not be available until mid-October (7). No trials have evaluated the combination of rAd26-rAd5 and BBIBP-CorV.

This study will attempt to determine whether administration of a heterologous regimen combining a first dose of Gam-COVID-Vac with a second dose of ChAdOx1 nCoV-19 or BBIBP-CorV results in non-inferior immunogenicity to the homologous regimen used.

The present protocol is therefore oriented to respond to a practical management need and to guarantee the best possible protection to the population through two doses, which is what is considered worldwide as "complete vaccination" according to WHO for the vaccines used by Argentina. The proposed protocol is a pragmatic and public health oriented clinical trial, whose primary objective is to establish whether there are indicators that allow the implementation of a heterologous vaccination scheme. For this, a surrogate endpoint will be used, which is immunogenicity measured by the presence of antibodies against protein S. In addition, the safety of the combination will be evaluated in terms of monitoring self-reported and non-self-reported clinical events by patients.

• Study Type: Interventional
• Enrollment (Actual): 192
• Phase: Phase 2

Contacts and Locations

Study Locations

• Argentina
  • Ciudad Autónoma de Buenos Aires, Argentina, 1284
    • Ministerio de Salud de la Ciudad Autónoma de Buenos Aires

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Persons who have received a dose of Gam-COVID-Vac more than 30 days and less than 90 days ago.
• Age between 21 and 65 years.
• Both genders.
• Who have voluntarily agreed to participate in the clinical trial and have provided informed consent.

Exclusion Criteria:

• Known history of COVID in the 6 months prior to study inclusion.
• Known or suspected immunocompromised status by the study investigator for any cause.
• Use of oral or parenteral corticosteroids in the last 30 days.
• Known history of allergy to any vaccine.
• History of anaphylaxis.
• Pregnant or lactating women.
• Known history of autoimmune diseases.
• Persons under treatment for any neoplastic disease within the last 6 months.
• Any serious illness or condition at the discretion of the study investigator (including but not limited to the presence of chronic obstructive pulmonary disease, heart failure, poorly controlled hypertension, poorly controlled diabetes, renal failure).
• Planned medical procedures within two months of randomisation.
• Previous vaccination within the last 30 days with any vaccine.
• Known participation in an ongoing clinical trial.
• Ongoing acute illness.
• Fever (≥37.8 C) at the time of randomisation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Gam-COVID-Vac / Gam-COVID-Vac	Drug: Gam-COVID-Vac / Gam-COVID-Vac; A comparison of antibody levels against protein S will be performed using the Gam-COVID-Vac / Gam-COVID-Vac group as a control group and the Gam-COVID-Vac / ChAdOx1 nCoV-19 and Gam-COVID-Vac / BBIBP-CorV groups as comparators.; Other Names: Gam-COVID-Vac / ChAdOx1 nCoV-19; Gam-COVID-Vac / BBIBP-CorV
Active Comparator: Gam-COVID-Vac / ChAdOx1 nCoV-19	Drug: Gam-COVID-Vac / Gam-COVID-Vac; A comparison of antibody levels against protein S will be performed using the Gam-COVID-Vac / Gam-COVID-Vac group as a control group and the Gam-COVID-Vac / ChAdOx1 nCoV-19 and Gam-COVID-Vac / BBIBP-CorV groups as comparators.; Other Names: Gam-COVID-Vac / ChAdOx1 nCoV-19; Gam-COVID-Vac / BBIBP-CorV
Active Comparator: Gam-COVID-Vac / BBIBP-CorV	Drug: Gam-COVID-Vac / Gam-COVID-Vac; A comparison of antibody levels against protein S will be performed using the Gam-COVID-Vac / Gam-COVID-Vac group as a control group and the Gam-COVID-Vac / ChAdOx1 nCoV-19 and Gam-COVID-Vac / BBIBP-CorV groups as comparators.; Other Names: Gam-COVID-Vac / ChAdOx1 nCoV-19; Gam-COVID-Vac / BBIBP-CorV

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ELISA assessment of IgG anti Spike (UI/ml)	To determine whether a heterologous vaccination regimen in individuals with no known previous history of COVID-19 is non-inferior to that observed with currently used counterpart regimens. The determination of the antibody concentration in each of the study arms will be assessed by measuring the IgG antibody concentration using ELISA expressed in IU/ml.	28 days
Serious adverse events Adverse events of special interest	To report the combine and specific rate of serious adverse defined as death for any reason, any life-threatening event or any event that require inpatient hospitalization.	28 days

Secondary Outcome Measures

Outcome Measure	Time Frame
Neutralising antibodies against SARS-CoV-2	28 days

Collaborators and Investigators

• Sponsor: Ministerio de Salud de Ciudad Autónoma de Buenos Aires

Study record dates

Study Major Dates

• Study Start (Actual): July 5, 2021
• Primary Completion (Actual): August 5, 2021
• Study Completion (Actual): August 15, 2021

Study Registration Dates

• First Submitted: July 8, 2021
• First Submitted That Met QC Criteria: July 13, 2021
• First Posted (Actual): July 15, 2021

Study Record Updates

• Last Update Posted (Actual): August 20, 2021
• Last Update Submitted That Met QC Criteria: August 18, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Keywords: COVID-19 Serological Testing
• Additional Relevant MeSH Terms: Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Virus Diseases; Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Pneumonia, Viral; Pneumonia; Lung Diseases; COVID-19
• Other Study ID Numbers: 5143

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No