A single-centre, observational study to evaluate immune response to Covid-19 vaccines in immunocompromised patients with haematological disorders (COVAC-IC)

Objective To evaluate immunological response to Covid-19 vaccines in immunocompromised haematology patients and compare with immunocompetent healthy controls Design We compared total Anti-SARS-CoV-2 spike antibody and T cell response in 45 immunocompromised haematology patients with 30 healthy adults following 2 doses of Covid-19 vaccine for 3 -5 months at 30 day intervals Setting Single Centre, University Hospital, United Kingdom, March 2021-December 2021 Main Outcome measures Peak quantitative total spike-specific antibody and cellular responses Results We found 1. Non - significant difference in T cell and total Anti-SARS-CoV-2 S antibody response between study and control group patients 2. Six (13%) study group participants did not have detectable Total Anti-SARS –Cov-2 S antibodies at any time point throughout the study monitoring period. 3. Three (7%) of the study group participants had no response, even after additional booster doses of Covid-19 vaccine. 4. All (100%) of the control group had detectable Anti-SARS-Cov-2 S antibodies after 2 doses of Covid-19 vaccine. 5. No participant died or was hospitalised due to severe Covid-19 infection during the study period. This included study group participants who had no antibody response at any time point. Conclusions Though there was a non - significant difference in T cell and total Anti-SARS-CoV-2 S antibody response between immunocompromised patients and healthy controls this did not result in any severe infection or Covid-19 related mortality in our study cohort. We did not identify any patient-specific factor (age, gender), specific haematological condition or treatment as determinant of response. Covid-19 vaccination was well tolerated without major side effects in both groups. What was already known about this topic prior to starting this study there were no studies to confirm immunological response following Covid-19 vaccination in immunocompromised haematology patients. During the conduct of our study there have been publications from researchers confirming blunted serological response in 62-66% of immunocompromised haematology patients compared to 74-95% in healthy controls. What this study adds Our study did not identify a significant difference in serological or T cell response between immunocompromised and healthy groups. Though 13% of immunocompromised patients had no response to Covid-19 vaccination none of them suffered from severe Covid-19 infection. We believe T cell response to Covid-19 vaccination has an important role in providing protective efficacy against Covid-19. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study is funded by the University Hospitals of North Midlands Research Charitable Fund. The study was sponsored by the Research and Innovation Directorate at University Hospitals of North Midlands. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: London Bridge Research Ethics Committee, reference 21/HRA/0304 I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data is available upon request. All information governance regulations were followed