Stellenbosch University (SU) is part of a large international research trial testing one of the most promising Covid-19 vaccine candidates currently available.
This vaccine (ChAdOx1 nCoV-19) was developed by Oxford University in the United Kingdom (UK) and is currently being tested at seven sites in South Africa, along with the UK and Brazil. The study is funded by the Bill & Melinda Gates Foundation and in South Africa is led by Prof Shabir Madhi of the University of the Witwatersrand.
Dr Shaun Barnabas of SU's Faculty of Medicine and Health Sciences (FMHS) is leading the Tygerberg trial site in Cape Town.
“The Faculty does well with infectious disease research and, because of this, we are comfortable conducting cutting-edge vaccine studies," says Barnabas, who is based at the FMHS' Department of Paediatrics and Child Health. “Our strength lies in conducting vaccine studies safely and rapidly. The infrastructure, reputation for pioneering work (especially in HIV and TB) and the relationships we have built allow us to compete with other big sites in South Africa."
This history has led to the Faculty's involvement in the randomised, placebo-controlled phase I/II trial of a prominent Covid-19 vaccine candidate. The vaccine is based on a chimpanzee adenovirus (which is often used in the development of human vaccines). This, and the fact that the virus can't replicate itself, should enhance the safety profile.
In the UK nearly 1 000 volunteers have already received the test vaccine and initial results published in The Lancet were promising. South Africa is enrolling just over 2 000 people nationally and the Tygerberg site plans to enrol 200, of which approximately 150 have been enrolled thus far.
“It's a mix of people and recruitment has been straightforward. We are looking for people representative of the general population, healthy with no comorbidities," says Barnabas. “We are recruiting from the surrounding community with the help of Community Advisory Boards. We've also had interest from healthcare workers – they see it as a one-in-two chance of receiving one of the most promising vaccines tested thus far."
Participants are screened for antibodies and also given a nasal swab to test for active disease. Barnabas explains that having had previous Covid-19 infection is not exclusionary, because there is no good data yet on whether previous infection actually provides protection.
“We don't know if natural disease leads to protection. The information on antibodies is unclear. We don't know what level of protection is needed or how specific the antibody tests need to be. We don't know if those people are at the same risk as someone who has never had it, or at a higher or lower risk. So they are eligible for the study."
Volunteers are also tested for co-morbidities – specifically hepatitis B, diabetes and HIV – and asked to disclose other conditions like hypertension or asthma.
The study involves two doses of the test vaccine given a month apart. It is hoped that enrolment will be completed by mid-October and immunology testing will be done in the UK after administration of the second dose.
“We should have some results in the first quarter of 2021," says Barnabas.
Due to the urgency of finding a vaccine, most studies are being carried out at a relatively rapid pace. However, this does not mean that safety can be compromised. The UK arm of the trial was recently paused due to an adverse event in a participant. This has been investigated and the study has recommenced.
“Thousands of people enrol in these studies, therefore the chances of someone developing something completely coincidentally is relatively high," explains Barnabas. “Any adverse event results in a global pause. There is a huge emphasis on safety and very high-level monitoring. There is also good communication between the sites."
In South Africa the study is closely monitored by the South African Health Products Regulatory Authority, the Data Safety and Monitoring Board and other regulatory authorities, as well as institutional ethics committees.
“South Africa is a research-intensive country when it comes to infectious diseases and vaccines," says Barnabas. “I think our involvement in this trial will boost our chances of accessing a successful vaccine when available. I believe we must use our excellent resources to contribute to developing a vaccine against Covid-19. It's about being a good global citizen.
“A vaccine is the best way to overcome the pandemic and allow normal life to resume."