Professor Sarah explains how T-cells overcome corona disease


WASHINGTON: President Donald Trump’s administration is considering fast-tracking an experimental coronavirus vaccine from the UK for use in America ahead of the presidential election, it has been reported.

Human trials of the coronavirus vaccine candidate being developed at the University of Oxford suggest it is safe and induces an immune response to Covid-19. Early results indicate the jab could provide double protection – generating an immune response which stimulates the body to produce both an antibody and T-cell response.

Sarah Gilbert

But what is the US president considering, what does the vaccine do and how does it work? A report in the Financial Times said he was considering bypassing normal US regulatory standards to fast-track the coronavirus vaccine being developed at the University of Oxford for use in America.

The paper said one option being explored would involve the US Food and Drug Administration awarding “emergency use authorisation” to a vaccine in October. The Financial Times reported that the US government’s scientific agencies have said a vaccine would need to be studied in 30,000 people to pass the threshold for authorisation. The Oxford vaccine is recruiting around 12,000 people for the next phase of human trials.

The vaccine – called ChAdOx1 nCoV-19 – uses a weakened version of a common cold virus (adenovirus) which causes infections in chimpanzees.

It has been genetically changed so it is impossible for it to grow in humans. It is hoped the vaccine will make the body recognise and develop an immune response to the spike protein – recognisable in images of the virus – that will help stop Covid-19 from entering human cells and therefore prevent infection.

With questions remaining about the duration of the antibody response to Covid-19, research suggests T-cells have a more important role in offering protection against the disease.

Sarah Gilbert, professor of vaccinology at Oxford University, explained that T-cells recognise and kill cells that have been taken over by a virus and been turned into little “virus factories”.

She added: “The two systems working together are completely complementary, first of all stopping infection coming in, and if (the virus) does get past the antibodies, (T-cells) destroy the cells that the virus has taken over.” It is not yet known whether the Oxford vaccine candidate provides long-term immunity.