Mbabane: The current COVID-19 vaccine trials in South Africa revealed shocking information that far more people are infected but asymptomatic than previously thought.
This is feedback from Professor Shabir Mahdi from the University of Witwatersrand, who is leading South Africa’s first COVID-19 vaccine trial.
According to Mybroadband Mahdi said between 50% and 66% of adults who are infected with COVID-19 are completely asymptomatic.
In children, this is even higher – around 80% of all children who are infected are asymptomatic.
“The majority of COVID-19 infections are going unnoticed,” Mahdi said, adding that only around 10% of all COVID-19 cases are officially reported.
Eswatini has also seen an increase in number of asymptomatic cases, most cases recorded among young people of 0-29 years have shown to be asymptomatic. As at July 9, 2020 Eswatini had recorded 1213 cases with 495 cases of age group from 0-29 years.
Speaking to CNBC Africa, Mahdi said they faced an unexpected challenge because of the rapid rate at which the COVID-19 virus is spreading in areas where the trials are conducted.
Part of the enrollment process for the COVID-19 vaccine trial involves the screening of individuals to see if they are infected or have previously been infected with the virus.
To their surprise, the researchers identified a much higher-than-anticipated percentage of people who have been infected by the virus but who were asymptomatic.
He said they have now tailored their enrollment process to include stricter screening to ensure people who participate in the study did not have the virus.
This is needed to accurately assess the effectiveness of the vaccine which is aimed at people who have never had COVID-19.
Mahdi explained in an article that the study in South Africa is for a non-replicating vector base COVID-19 vaccine that was developed by the Jenner Institute at the University of Oxford.
Pre-clinical studies of this vaccine candidate have demonstrated initial evidence of its safety, as well as its ability to protect against COVID-19 disease.
The second part according to Mahdi is to do an analysis to determine whether the vaccine actually does protect against COVID-19.
“Specifically, we will be testing if the vaccine efficacy is at least 60% – that is by being vaccinated your risk for developing COVID-19 will be reduced by at least 60% if not more,” he said.
Madhi said they will probably be able to provide an answer as to whether this vaccine works and protects against COVID-19 by the end of November this year.
In the worst-case scenario, it might take us a bit longer – probably into the second quarter of next year.
Madhi cautioned that the fact that they’re embarking on a clinical trial doesn’t mean that they’re going to have a vaccine that’s going to protect against COVID-19.