Solidarity Trial Vaccines

The Solidarity Trial Vaccines (STV) is an international, multi center, multi vaccine, adaptive, shared placebo, event driven, individually randomized controlled clinical trial that aims to evaluate the efficacy and safety of promising new COVID-19 vaccines.

The primary objective is to evaluate the effect of each vaccine on reducing the rate of virologically confirmed COVID-19 disease, regardless of severity.

Key features of the trial include:

mobile trial sites to enable reaching people in remote areas and achieve more equitable recruitment
interim analyses to identify better performing candidates and to eliminate those that are performing poorly against pre-specified statistical thresholds
long-term follow-up to increase the rigour of results and enable formal evaluation of efficacy vs. severe disease and duration of efficacy

16 December 2021

Solidarity Trial Vaccines (STV)

Why do we need a global trial of COVID-19 vaccines?

The STV aims to uncover second-generation vaccines with greater efficacy, greater protection against variants of concern, offering longer duration of protection, and innovations in storage or routes of needle-free administration.

More vaccines need to be identified and evaluated to provide a range of options for different circumstances around the world. New COVID-19 variants may develop the ability to escape the immunity provided by existing COVID vaccines. Clinical evaluation of new vaccines is therefore even more important to ensure that safe and effective vaccines can be deployed around the world.

How are candidate vaccines included in the STV selected?

An independent panel of scientists and vaccine experts is tasked with the review, selection and the prioritization of vaccines that have been tested in phase 2 clinical trials.

The selection of candidate vaccines for the STV involves evaluation of pre-defined criteria, including:

their safety and proven potential for effectiveness
stability of the vaccine
demonstration that they can be stored and transported easily under normal conditions
availability - whether they can be produced quickly for global distribution
the ease with which they can be given to individuals (how the vaccines are given, the number of doses etc)

To date the independent vaccine prioritization advisory group has reviewed the evidence generated on approximately 20 candidate vaccines. Of these, two candidate vaccines have been approved for inclusion in the STV. These are a spike adjuvanted vaccine developed by Medigen, and a DNA vaccine encoding the spike protein developed by Inovio.

Two additional vaccines, a SARS-CoV-2 self-amplifying RNA vaccine from Arcturus, and a SARS-CoV-2 live attenuated vaccine from Codagenix and the Serum Institute of India, may enter the STV soon if additional evidence and documentation has been reviewed and deemed satisfactory by the independent vaccine prioritization advisory group,

It is expected that other candidate vaccines under consideration by the vaccine prioritization advisory group may be added to the STV trial in late 2021 and during 2022.

How will the STV be implemented?

National Ministries of Health and WHO are co-sponsoring the trial. A principal investigator, nominated by the Ministry of Health in each country, will lead the national team delivering the study. National teams are already working closely with scientists, public health professionals, community leaders and local communities to plan and deliver the trial.

Prior to starting, all relevant ethical and regulatory approvals have been obtained for all sites in the countries participating in the trial

The Solidarity Trial Vaccines (STV) has specific features that make it more flexible and adaptive than standard/traditional trials, for example:

New candidate vaccines can be added: New candidate vaccines that meet WHO prioritization criteria can be added to the trial as these become available.
Choice of study population and location of trial: Study sites can be fixed or mobile and the trial team overseeing the trial can change the number of sites and the number of people it is aiming to recruit (sample size).

Where is the STV currently active?

The STV has started recruitment in selected sites in the Philippines, Mali and Colombia.

All national teams have experience and expertise in conducting clinical trials, are trained in Good Clinical Practice (GCP), and all have implemented WHO guidance for good participatory practices for multi stakeholder engagement.

The trial will be expanded to include new countries. WHO is currently reviewing requests from additional countries that have expressed interest in delivering the trial.

Who can take part in the STV?

Anyone aged 16 and over living in an area with high COVID-19 rates, who has not had COVID-19 and who has not received a COVID-19 vaccination may volunteer to take part.

The study team will check volunteers’ eligibility and obtain their informed consent or assent (for those aged 16-18) at registration.

All participants will be carefully followed up weekly by the trial team for at least one year.

STV governance

In order to enhance global coordination and collaboration, WHO has established an independent governance structure comprising:

An International Steering Committee to govern the conduct of the trial in accordance with the international trial protocol. It is composed of representatives from participating country governments who nominate two members – a representative of the Ministry of Health (or national Medical Research Council, or equivalent) and the national Principal Investigator. These representatives are jointly responsible for obtaining, at national and local levels, ethical approvals and any other relevant permissions, and for ensuring the commitment of collaborating trial sites.

An Executive Group of the Steering Committee composed of independent international experts to ensure the study is being conducted appropriately and to ensure that the International Steering Committee is regularly updated. The Executive Group will decide on any required changes to trial arms.

A Global Data and Safety Monitoring Committee (DSMC) to analyse confidential trial data to determine the safety and efficacy of the vaccines being investigated. The DSMC is independent of the Steering Committee and of any co-sponsor or donor in order to safeguard the interests of participants and enhance the integrity and credibility of the trial.

A WHO Vaccine Prioritization Working Group, an independent group of experts providing advice on the selection of candidate vaccine(s) to be evaluated in the trial.

A WHO Trial Secretariat responsible for the global coordination of the trial and provision of technical support to participating countries in the following areas: