Outcomes Following SARS-CoV-2 Infection in Patients With Primary and Secondary Immunodeficiency in The United Kingdom (preprint)

Purpose: To define the burden of morbidity and mortality arising from COVID-19 in individuals with primary (PID) and secondary immunodeficiency (SID) in the United Kingdom. Methods In March 2020, the United Kingdom Primary Immunodeficiency Network (UKPIN) established a registry of cases to collate the outcomes of individuals with PID and SID following SARS-CoV-2 infection and treatment. Anonymised demographic data, pre-SARS-CoV-2 infection lymphocyte counts, co-morbidities, targeted treatments and outcomes were collected. Three groups were analysed in further detail: individuals with common variable immunodeficiency (CVID), individuals with any PID, including CVID, receiving immunoglobulin replacement therapy (IgRT) and individuals with secondary immunodeficiency. Results A total of 310 cases of SARS-CoV-2 infection in individuals with PID or SID have now been reported in the UK. The overall mortality within the cohort was 17.7% (n = 55/310). Individuals with CVID demonstrated an infection fatality rate (IFR) of 18.3% (n = 17/93), individuals with PID receiving IgRT had an IFR of 16.3% (n = 26/159) and individuals with SID, an IFR of 27.2% (n = 25/92). Individuals with PID and SID, had higher inpatient mortality and died at a younger age than the general population. Increasing age, low pre-SARS-CoV-2 infection lymphocyte count and the presence of common co-morbidities increased the risk of mortality in PID. Access to specific COVID-19 treatments in this cohort was limited: only 22.9% (n = 33/144) of patients admitted to hospital received dexamethasone, remdesivir, an anti-SARS-CoV-2 antibody-based therapeutic (e.g. REGN-COV2 or convalescent plasma) or tocilizumab as a monotherapy or in combination. Dexamethasone, remdesivir and anti-SARS-CoV-2 antibody-based therapeutics appeared efficacious in PID and SID. Conclusion Compared to the general population, individuals with PID or SID are at high risk of mortality following SARS-CoV-2 infection. Increasing age, low baseline lymphocyte count and the presence of co-morbidities are additional risk factors for poor outcome in this cohort.

ASSESSMENT OF WORKERS PERSONAL VULNERABILITY TO COVID-19 USING COVID-AGE (preprint)

Decisions on fitness for employment that entails a risk of contracting Covid-19 require an assessment of the workers personal vulnerability should infection occur. Using recently published UK data, we have developed a risk model that provides estimates of personal vulnerability to Covid-19 according to sex, age, ethnicity, and various comorbidities. Vulnerability from each risk factor is quantified in terms of its equivalence to added years of age. Addition of the impact from each risk factor to an individuals true age generates their "Covid-age", a summary measure representing the age of a healthy UK white male with equivalent vulnerability. We discuss important limitations of the model, including current scientific uncertainties and limitations on generalisability beyond the UK setting and its use beyond informing assessments of individual vulnerability in the workplace. As new evidence becomes available, some of these limitations can be addressed. The model does not remove the need for clinical judgement or for other important considerations when managing occupational risks from Covid-19.