When Oxford University announced that it had developed a promising vaccine called ‘ChAdOx1 nCoV-19’, many were hoping it would be the saving grace for a COVID-stricken world.
Dr Dave Fredericks, a critical-care physician at Groote Schuur hospital in Cape Town, was one of the first people to be enrolled in the vaccine trial when Wits and the University of Cape Town (UCT) rolled out testing in South Africa.
Through his involvement in the vaccine trial, Fredericks wants to be part of finding a solution to the pandemic. Having worked on the Covid frontlines since April, Fredericks has seen both young and old succumb to the virus. Seeing several of his colleagues contract the virus was also an eye-opener.
Being potentially exposed to Covid, Fredericks was curious to see if his body had developed antibodies to fight the virus. “I was screened and I found out that I was negative for antibodies. I realized the trial needs people from the frontline because people – like me – who are healthy but potentially exposed – will be able to provide answers about the efficacy of this vaccine,” he said.
HOW DOES THE OXFORD VACCINE WORK?
ChAdOx1 nCoV-19 is currently in its third phase of testing, with trials taking place in the UK, Brazil, US, Japan and South Africa. The vaccine is essentially made from a weakened version of an adenovirus – the virus that typically causes the common cold. Oxford researchers used a chimpanzee adenovirus, hence the name ChAdOx1.
Scientists then added genetic material – called spike glycoprotein – to the ChAdOx1 virus. Spike glycoprotein is usually found on the surface of the novel coronavirus and this is what gives the coronavirus its distinctive ‘spiky’ appearance. These spikes help the coronavirus invade cells, laying a path for infection in the body.
The virus has been engineered to mimic the coronavirus spike glycoprotein, and the hope is that when this adenovirus is injected into humans, the spike protein will induce the body’s immune system to respond and fight back should the person become infected with Covid-19. This would produce antibodies in the process.
“What they saw initially at Oxford is that there’s fairly good antibody formation with regards to the first dose.”
Dr Dave Fredericks
WHAT HAPPENS DURING THE VACCINE TRIAL?
“Different populations may respond differently to the vaccine, depending on genetic and other factors. Participants cannot be pregnant or diabetic, and in Cape Town they are not recruiting any HIV positive patients,” explains Fredericks.
A single dose is given into the deltoid muscle that covers the shoulder joint. Participants do not know if they have received the vaccine or a placebo. A second dose is administered 28 days later. This is followed by a series of six visits during a 12-month period during which antibody and blood tests are performed, as well as swabs to monitor the effectiveness of the vaccine.
Participants are also given a diary to document any swelling, redness, tenderness, or bruising. They must also monitor signs of fever, sweat, shortness of breath, loss of taste or smell, headaches and coughs. Fredericks said some of the potential side effects are muscle pain, fever, and sweat. He initially experienced minor swelling and pain, followed by fatigue and a slight headache. These side effects have now subsided and Fredericks feels fine.
In September, the trial was paused globally for a week ago after a participant fell ill in the UK. After it was found that the illness was unlikely to be related to the vaccine, international regulators – including the South African Health Products Regulatory Authority and the ethics committees from Wits and UCT – deemed the trials safe to resume.
HOW SOON CAN WE EXPECT A VACCINE?
“It’s unlikely that we’ll have any results within the next 12 months but it is important for South Africans to participate in the vaccine trials because the results are contributing to the global fight against this pandemic,” says Fredericks.
Presently, there are more than 100 projects around the world centered on the development of a COVID-19 vaccine. Massachusetts-based biotech company, Moderna Therapeutics, is currently in the human phase of its vaccine trial which has yielded promising results. However, Moderna’s chief executive officer, Stéphane Bancel, has warned that it was unlikely the vaccine would be available in the first half of 2021.
Healthcare and pharmaceutical giant, Johnson & Johnson, is working on a vaccine that builds on the technology that the company used to develop an Ebola vaccine. So far, the vaccine has prompted the formation of effective antibodies in monkeys.
WHAT NEXT FOR THE OXFORD VACCINE TRIAL?
Until a vaccine is found, however, Fredericks and other healthcare workers, as well as the Ministerial Advisory Committee for coronavirus vaccines, have stressed the need for mask-wearing, social distancing and regular sanitizing until a pharmaceutical solution has been found. This, Fredericks says, is essential to counter a second, devastating wave of Covid-19 infections.
As we await a vaccine, the mask, sanitizers and social distancing are here to stay.