SA professor involved in COVID-19 vaccine trial gives insight into research being done

Wits University is collaborating with the University of Oxford and the Oxford Jenner Institute on the South African leg of the trial for a coronavirus vaccine.

Leader of the vaccine trial Professor Shabir Madhi of the Vaccinology Department at Wits University says the vaccine is designed for two purposes.

“The way the study is designed is that we are trying to establish whether there is at least 60% efficacy. So we’ve got enough individuals participating and it allows us to assess whether there’s at least 60% efficacy because what is more important than efficacy is what we call the number of people that need to be vaccinated to prevent one illness. So that’s another measure that’s important from the public health perspective in that you can have a vaccine that’s 50% efficacious but it can prevent more people from becoming sick compared to having a vaccine that’s 90% efficacious but for a disease that is very rare”.

The vaccine trial began as the country has surpassed 100 000 COVID-19 infections and 2 000 deaths mark.

The trails, which aim to find a vaccine that will prevent infection by SARS-CoV-2 – the virus that causes COVID-19, were the first in Africa. The vaccine is made from the adenovirus, which is a weakened and non-replicating version of a common cold virus. The vaccine has been engineered to express the SARS-CoV-2 spike protein.

Two thousand people will be enrolled over the next few weeks.

The vaccine is currently being evaluated in a larger clinical trial in the United Kingdom, where more than 4 000 participants have been enrolled. A similar study with 5 000 participants will soon start in Brazil.  The President and Chief Executive Officer at the SA Medical Research Council which has sponsored the trial, Professor Glenda Gray, says they will also be monitoring the trial in Brazil.

“Brazil is struggling from what I can see in the media but what’s very exciting about Brazil is that they are involved in three or four vaccine endeavours and I think that is going to be very exciting to see how Brazil responds and whether it works and work with SA in that setting. As Shabir says no epidemic is the same and it is very hard to draw parallels because we all have our own issue and we all have our own struggles and we also have other health and economic issues that are quite different”.

Madhi says while South Africa and Brazil have similarities, COVID-19 responses of both countries have been different and they are hoping for better results.

“South Africa has been much more aggressive than Brazil in terms of trying to slow the rate of transmission of the virus, but these are both complex societies both Brazil as well as SA. I don’t think it’s a correct thing to make comparisons between countries. It is unfortunate that Brazil seems to be ahead of the curve compared to where we are in SA and we can only hope that what we experience in SA in the next month doesn’t sort of mirror what is happening in Brazil at this point in time”.

While all hopes are for a successful vaccine at the end of the trial, it might be halted midway should challenges emerge. Madhi says an Independent Data Safety Monitoring Committee is watching the trials in the United Kingdom, South Africa and in Brazil.

“If we find a huge number of people that are infected over a short period of time so if we reach 42 cases very rapidly without having completely finished enrolling the 2 000 individuals as an example, we will then be able to see whether the vaccine works or not and at that point we will stop enrolling further into the study. The study can be prematurely terminated either because there’s a safety issue or alternatively if we find that we are getting large number of cases over a short period of time, which allows us to do an assessment as to whether the vaccine works or not”.

An even larger study involving 30 000 participants is planned for the United States at a later stage.