A new home-testing kit designed to measure levels of T cells against the virus that causes COVID-19 has been launched on the UK market. It is the first time such a kit has been available anywhere in the world.
Cardiff-based biotech company ImmunoServ created the product, called Immuno-T, to give people the option of purchasing a test to measure their T cell levels against COVID-19 at home, without visiting a clinic.
Immunity to COVID-19 is often described in terms of antibodies produced by the immune system to recognise and bind to the spike protein on the surface of the virus. However, some people do not make antibodies in response to either infection or vaccination, or make too few to be able to protect themselves this way. This can be especially true of people who have a condition that affects their immune system, or who are being treated with drugs that suppress the immune response. Examples include certain blood cancers, organ transplants or inflammatory conditions such as rheumatoid arthritis.
But a lack of antibodies doesn’t necessarily mean someone is not protected against the virus. Our immune system also uses T cells to fight disease, and these cells are often present even in people who are not able to make antibodies. A T cell test has until now not been available for people to buy and use at home.
Developed by specialists in T cell immunity, the Immuno-T test uses tiny fragments of the SARS-CoV-2 virus to see if a finger-prick blood sample contains T cells that help protect against COVID-19. The test can be used for monitoring an individual’s immune response after COVID-19 infection or vaccination. If the blood sample contains T cells that recognise the virus, those T cells respond by releasing a molecule called interferon-gamma. The amount of interferon-gamma detected gives an indication of how well a person is protected from future infection.
The test was developed in collaboration with researchers at Cardiff University and was funded with support from InnovateUK and National Core Studies Immunity.
A paper in the journal Nature Communications, published at the end of September, provided further evidence on the test's effectiveness. More than 300 volunteers were recruited from across the UK in early 2022 to establish how well the test could predict level of protection from COVID-19. The researchers found that people with the largest T cell response to the virus were best protected over the following three months, regardless of their levels of antibodies to the virus.
It is important to note that the correlation between T cell levels and protection against future infection with COVID-19 is still being understood, and there is no established level of either T cells or antibodies that can be guaranteed to provide protection from the virus.
Dr James Hindley, CEO of ImmunoServ, commented:
The team here at ImmunoServ have worked very hard over the last year to develop and deliver a COVID-19 T cell test that could be easy enough for use by the general public, as well as being accessible to anyone in the UK. I’m very pleased to see this ambition realised.