The first participants in South Africa’s first clinical trial for a vaccine against Covid-19 will be vaccinated this week.

The first clinical trial in South Africa and on the continent for a Covid-19 vaccine was announced on June 23, at a virtual press conference hosted by the University of the Witwatersrand (Wits).

The South African Ox1Cov-19 vaccine VIDA-trial aims to find a vaccine that will prevent infection by SARS-CoV-2, the virus that causes Covid-19.

In South Africa, more than 100 000 people have been diagnosed with Covid-19, while nearly 2 000 people have died.

Wits Professor of Vaccinology and South Africa Medical Research Council (SAMRC) Vaccines and Infectious Diseases Analytics Research Unit (VIDA) director Shabir Madhi is leading the South African Ox1Cov-19 vaccine VIDA-Trial.

Wits is collaborating with the University of Oxford and the Oxford Jenner Institute in England on the South African trial.

“This is a landmark moment for South Africa and Africa at this stage of the Covid-19 pandemic. As we enter winter in South Africa and pressure increases on public hospitals, now more than ever, we need a vaccine to prevent infection by Covid-19,” said Madhi at the launch of the South African Ox1Cov-19 Vaccine VIDA-Trial, which is being run at multiple sites in South Africa.

“We began screening participants for the South vaccine trial last week and the first participants will be vaccinated this week,” he added.

Prior to launch, the South African study was subject to rigorous review and has been approved by the South African Health Products Regulatory Authority (SAHPRA) and the Human Research Ethics Committee of Wits.

Moreover, after eliciting and considering public comment, the Department of Agriculture, Forestry and Fisheries approved import of the investigational vaccine for use in the trial.

SOUTH AFRICAN PARTICIPATION IN INTERNATIONAL TRIALS

The vaccine is already being evaluated in a large clinical trial in the UK where more than 4 000 participants have already been enrolled. In addition to the South African study, similar and related studies are about to start in Brazil.

An even larger study of the same vaccine involving up to 30 000 participants is planned in the US.

“It is essential that vaccine studies are performed in southern hemisphere countries, including in the African region, concurrently with studies in northern hemisphere countries.

"This allows evaluation of the efficacy and safety of candidate vaccines to be assessed in a global context, failing which the introduction of many life-saving vaccines into public immunisation programmes for low-middle income countries frequently lag behind those in high-income countries,” says SAHPRA chair of the Wits Reproductive Health and HIV Institute (Wits RHI) executive director Professor Helen Rees.

Rees also co-directs the Wits African Leadership in Vaccinology Excellence (Alive) flagship programme and is engaged in global discussions with Gavi, the Vaccine Alliance and the World Health Organization to ensure equitable access for all countries, including those in Africa, should a successful vaccine be developed.

VACCINE INFO

The technical name of the vaccine is ChAdOx1 nCoV-19, as it is made from a virus called ChAdOx1, which is a weakened and non-replicating version of a common cold virus (adenovirus). The vaccine has been engineered to express the SARS-CoV-2 spike protein.

The vaccine was developed at the Oxford Jenner Institute and is currently on trial in the UK, where over 4 000 participants are already enrolled into the clinical trial and enrolment of an additional 10 000 participants is planned.

The vaccine being used in the South African trial is the same as that being used in the UK and Brazil.

The vaccine was made by adding genetic material – called spike glycoprotein – that is expressed on the surface of SARS-CoV-2 to the ChAdOx1 virus.

This spike glycoprotein is usually found on the surface of the novel coronavirus and is what gives the coronavirus its distinct spiky appearance.

These spikes play an essential role in laying a path for infection by the coronavirus. The virus that causes Covid-19 uses this spike protein to bind to ACE2 receptors on human cells.

ACE2 is a protein on the surface of many cell types. It is an enzyme that generates small proteins that then go on to regulate functions in the cell. In this way, the virus gains entry to the cells in the human body and causes Covid-19 infection.

Researchers have shown that antibodies produced against sections of the spike protein after natural infection are able to neutralise or kill the virus when tested in the laboratory.  

By vaccinating volunteers with ChAdOx1 nCoV-19, scientists hope to make the human body recognise and develop an immune response to the spike glycoprotein that will help stop the SARS-CoV-2 virus from entering human cells and causing Covid-19.

LOCAL APPLICATION

In addition to the more than 4 000 people already vaccinated in the UK with the ChAdOx1 nCoV-19 vaccine, other vaccines made from the ChAdOx1 virus have also been given to more than 320 people to date. These vaccines have been shown to be safe and well-tolerated, although they can cause temporary side effects, such as a temperature, headache or a sore arm.

There are currently over 100 candidate Covid vaccines in development around the world and many of South Africa’s best vaccine research institutions will soon be involved in a range of vaccine studies evaluating other types of potential Covid vaccines.