Mortality and burden of post-COVID-19 syndrome have reduced with time across SARS-CoV-2 variants in haematology patients.

Haematology patients contracting SARS-CoV-2 were identified at the start of the pandemic to be at higher risk of death or of persistent symptoms (post-COVID-19 syndrome). As variants with altered pathogenicity have emerged, uncertainty remains around how that risk has changed. We prospectively set up a dedicated post-COVID-19 clinic to monitor haematology patients infected with COVID-19 from the start of the pandemic. In total, 128 patients were identified and telephone interviews were conducted with 94 of 95 survivors. Ninety-day mortality attributed to COVID-19 has fallen sequentially from 42% for the Original and Alpha strains to 9% and to 2% for the Delta and Omicron variants respectively. Furthermore, the risk of post-COVID-19 syndrome in survivors has fallen from 46% for the Original or Alpha strains to 35% for Delta and 14% for the Omicron strain. Since vaccine uptake has been nearly universal in haematology patients, it is not possible to determine whether improved outcomes reflect the reduced pathogenicity of the virus, or widespread vaccine deployment. Whilst mortality and morbidity remain higher in haematology patients than in the general population, our data suggest that the absolute risks are now significantly lower. Given this trend, we believe clinicians should initiate conversations about risk with their patients on whether to maintain any self-imposed social isolation.