SARS-CoV-2 immunity measured in single blood test

Scientists at Cardiff University, in collaboration with the city-based biotech Immunoserve, have developed a test to measure both the T-cell and antibody response to SARS-CoV-2 in a single blood sample.

Dr Martin Scurr, a research associate at Cardiff University’s School of Medicine and lead author on the study, said: “COVID-19 infection rates remain alarmingly high – and it is clear infection even after vaccination is an issue. To help control future outbreaks and identify at-risk individuals, it is important to understand the exact make-up of the immune response to COVID.

“Our test accurately detects both the T-cell and antibody response to the virus in one blood sample. Together these indicators represent a powerful measure of immunity from COVID-19.

“The test can be made widely available, is easy to employ and cost effective and should play a very useful role in monitoring this pandemic, for instance by identifying individuals at greater need of booster jabs.”

The test proved most useful in monitoring immune responses in patients considered more at risk from COVID-19, even after vaccination. The study found the second vaccine dose was essential for cancer patients. Among cancer patients recruited from Velindre Cancer Centre in Cardiff, two doses induced T-cell and antibody responses to equivalent levels as healthy donors.

However, it is clear that in some cancer patients there is a dramatic fall of in immune responses at three months, not seen in healthy controls, and highlights the importance of monitoring these responses.

Professor Andrew Godkin, co-senior author from Cardiff University and the University Hospital of Wales, said: “Without this sort of information there is uncertainty around whether repeated booster vaccinations will be required in future, and who in particular will need them. This data is crucial for understanding how and when to offer re-vaccinations to different groups.”

The research team will also monitor whether T-cell and antibody responses induced by vaccination can protect against SARS-CoV-2 mutant variants, including the Delta variant that is currently the most prevalent in the UK.

Danny Altmann, Professor of Immunology at Imperial University, said: “This study is important in both demonstrating the ease of measuring immune responses using a whole blood approach, but also the importance of monitoring susceptible individuals and healthy controls for differences in vaccine response and future potential loss of protection. Long-term monitoring will be crucial to understand and quantify this problem.”

The research was funded by UK Research and Innovation as part of its response to the pandemic, along with the Medical Research Council and Cancer Research Wales.

Published in Immunology

More information online