The University of the Witwatersrand has begun the first COVID-19 vaccine trial in South Africa in partnership with the University of Oxford.
This trial will see South African volunteers administered with a COVID-19 vaccine – the safety and efficacy of which will be tested before it is made available to the public.
While trials have begun, it will still be more than a year before the vaccine will become publicly available, provided it is found to be effective against the coronavirus that causes COVID-19.
This is according to Wits University professor of vaccinology Shabir Madhi, who said at the announcement of the trial that the vaccine is only expected to be publicly available in the second half of 2021.
In addition to his role at the university, Madhi is also director of the South Africa Medical Research Council (SAMRC) Vaccines and Infectious Diseases Analytics Research Unit.
“So when is it possible that the vaccine might become available to the public?” Madhi said.
“It’s a difficult question, but my best guess right now is probably around about September or October of next year, provided that we actually show that the vaccine works this year.”
“The longer that we delay being able to show that the vaccine actually works, the further it pushes out the timeline that the vaccine would become available,” he said.
Madhi said that the vaccine was being tested in South Africa to determine whether it is safe and efficacious specifically within the South African context.
This will adequately equip scientists with the evidence to promote the use of the vaccine in the country, he said.
How the vaccine works
The COVID-19 vaccine being tested in South Africa is the Ox1Cov-19 (technically named “ChAdOx1 nCoV-19”) vaccine developed by the University of Oxford.
This vaccine has been engineered to express the SARS-CoV-2 spike protein, which is found on the surface of the novel coronavirus and gives the virus its distinct spiky appearance.
The coronavirus which causes COVID-19 uses these spikes to bind to ACE2 receptors on human cells, causing an infection.
Researchers have shown that antibodies produced against sections of the spike protein after natural infection are able to kill the virus when tested in the laboratory.
“The vaccine is not going to cause someone to get infected with the virus,” Madhi said.
“The vaccine that we are evaluating is not a live vaccine – it doesn’t replicate in the human body.”
“All that it does is deliver the protein that is of interest to us to the body and present it to the immune system,” he said.
Once presented, scientists hope that the subject’s immune system would recognise the protein as being foreign and mount a response to it – developing antibodies which would protect from this spike protein.
“We hope that those antibodies will protect someone from developing severe disease,” Madhi said.
“It might not protect someone from becoming infected, but it will protect someone from being clinically ill, which is the main outcome of interest for us.”