UK to trial effectiveness of T-cell immunity test kits

Study could reignite hopes that coronavirus immunity 'passports' may be possible, allowing protected people to safely return to work

Thousands of people will be recruited to find out whether they have acquired T-cell immunity to coronavirus under a new trial arranged by a group of British scientists and Public Health England (PHE).

Scientists had originally hoped that infected individuals would develop antibodies which would prevent them getting a second bout of the disease, but recent studies suggest they vanish after a few months.

However, alternative research has found that people infected with a similar Sars-type virus develop T-cell immunity that can last up to 17 years, meaning far more people may be immune for far longer (see box below for details of how antibodies and T-cells work).

PHE has partnered diagnostics company Oxford Immunotec, among others, to evaluate whether their testing kits can adequately pick up T-cell immunity in a large-scale trial involving 3,500 healthcare workers and police officers.

The trial could reignite hopes that immunity "passports" may be possible, allowing protected people to safely return to work. 

Oxford Immunotec believes it could help governments plan any future restrictions around a better understanding of population-wide immunity, roll out more comprehensive testing programmes and allow freer movement in the community or internationally. 

People would be able to carry out the test at home to know whether they were protected from the virus. 

Peter Wrighton-Smith, the CEO of Oxford Immunotec, said: "We believe a successful trial will yield important information about our test, to further our knowledge of how it works and help us to develop the test further."

Recent studies have suggested the immune system can be primed by other coronaviruses, such as the common cold, giving the body a head start in fighting off Covid-19.

Research shows that a separate part of the immune system, T-cells, respond to chains of amino acids produced by different types of coronaviruses and may be responsible for stopping the virus in people who never show symptoms. 

Crucially, those T-cells die off in older people, which may be why they are far more likely to develop a more serious illness.

The vaccine being developed by Oxford University has been found not only to stimulate antibodies but also to boost T-cell response.

However, many more people may already have some protection, suggesting herd immunity will be easier and quicker to establish. A recent study suggested children may be protected from coronavirus because they catch so many colds.