South Africa launched its first Covid-19 vaccine trial this week, setting out to have close to 2 000 participants in Gauteng, and possibly the Western Cape, who will receive an experimental vaccine and be closely monitored in the hopes that 60% of trial participants develops immunity by vaccine. 

The trial is sponsored by the University of Oxford’s Jenner Institute in collaboration with the University of the Witwatersrand, will test the efficacy of the vaccine, whose technical name is ChAdOx1-nCOV-19.  

Funding for the trial, estimated by Madhi at R150-million, is from the SA Medical Research Council and the Bill and Melinda Gates Foundation. The National Department of Health has pledged its support, saying that the trial could not have come at a better time.  

“South Africa must always lead from the front. There would be no better time than today to actually launch this vaccine trial as the country has reached a landmark of over 100 000 infections recorded last night,” Director-General Dr Sandile Buthelezi said. 

The same trial is underway in the United Kingdom where more than 4 000 participants have enrolled, and in Brazil, where 5 000 participants have enrolled. A much larger study, with up to 30 000 participants, is planned for the United States. 

Herd immunity goal 

South Africa’s trial will test healthy volunteers aged between 18 and 65 from Covid-19 hotspots in the country’s metropoles where infection rates are highest. Another 50 people living with HIV will be tested, in order to assess the vaccine’s safety and efficacy in this vulnerable group.  

“We are trying to see if we can gain 60% immunity to the vaccine in this study. If it is lower, it will not be powerful enough to pass as a viable vaccine,” said Professor Shabir Madhi, who heads up the trial. Madhi is a Wits University vaccinology professor and director of the South Africa Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit.   

“Our best-case scenario is that we would have an answer [on the outcomes] of this particular vaccine by the end of the year,” Madhi said at a University of Witwatersrand virtual media briefing.  

Vaccine method 

However, should the vaccine succeed, it will only be accessible to the public in around the third quarter of 2021, Madhi stressed at yesterday’s media briefing.  

In the trial, half the participants in each group will receive the ChAdOx1-Cov19 vaccine and the other half (the control group) will receive a saline placebo. The objective is threefold – to investigate if the vaccine will protect against Covid-19, doesn’t cause unacceptable side effects‚ and if it induces satisfactory immune responses. 

This trial is planned over the next year, starting with the first group of 50 participants (concluded by mid-August), followed by the second group of 1 900 participants, and finally the third group of 50 HIV–positive participants.  

Group One will receive two doses of the vaccine, four weeks apart, while Group Two will receive a single dose, unless results from Group One indicates that two doses are required to get an adequate immune response. Group Three will receive two doses, four weeks apart  

After receiving the vaccine, the participants will record any symptoms for the next three weeks. Researchers will also follow-up fortnightly, taking blood samples and checking participants’ observations, which will be used to assess the immune response to the vaccine. – Health-e News