A new study will look at the immune response to natural coronavirus infection and vaccination in patients with antibody deficiency.

The Covid infection in patients with Antibody Deficiency (COVAD) study is part of a group of national studies examining the immune responses in patients considered at high risk of Covid-19.

Immunodeficiency patients are considered vulnerable or extremely vulnerable to the virus and have had to undertake preventative measures to minimise their risk of exposure to the virus, including shielding.

Patients with antibody deficiency do not make good responses – if any – to most vaccines, but it is not known whether they will respond to coronavirus jabs.

This study is part of the national effort to understand how well vaccines work in vulnerable patients

COVAD chief investigator, Alex Richter, professor of clinical immunology at the University of Birmingham, and consultant clinical immunologist at University Hospitals Birmingham NHS Foundation Trust, said: “Nationally, a number of patients with immunodeficiency have had severe or prolonged illness with Covid-19.

“Understanding why some patients do well and others don’t is so important.

“Being unable to clear the virus is not just a problem to the patient but is potentially a public health problem too.”

The team, led by the University of Birmingham, University Hospitals Birmingham NHS Foundation Trust, and University College London will be using Oxford Immunotec’s T-SPOT Covid test to test immunological responses.

Samples will be taken from patients to measure the presence and level of antibodies in the blood and anti-coronavirus T-cells.

Researchers say the results will be widely applicable to immunosuppressed patients and help inform the development of vaccination strategies as well as strengthen the understanding of risk for continuous virus transmission.

Co-principal investigator Siobhan Burns, professor of translational immunology at University College London, added: “This study is part of the national effort to understand how well vaccines work in vulnerable patients.

“We are also looking for persistent viral infections in our patients to understand whether this drives viral mutation.”

Professor Fiona Watt, executive chair of the Medical Research Council, part of UKRI, said: “This multi-partner study will explore a crucial area of COVID-19 research and tell us more about the immune response of immunodeficient individuals to natural COVID-19 infection and vaccination.

“The importance of this is two-fold: protecting some of the most vulnerable groups to severe effects of the disease, and understanding how the virus that causes Covid-19 may adapt within an individual who struggles to clear the virus.”

Professor Sinisa Savic, chairman of the UK Primary Immunodeficiency Network, said: “The findings of this study will be critical for developing future Covid-19 guidelines for care of patients with antibody deficiencies.”

The research will be conducted at immunodeficiency centres at NHS hospital trusts across the UK, in what will be the largest study of its kind in this rare patient group world-wide.

The centres will screen patients and will invite those who are eligible and meet specific criteria to join the trial.

If a patient is eligible for the study, their immunologist will write to them with more information, and then they can confirm whether they are willing to take part.