Favorable outcomes of COVID‐19 in vaccinated hematopoietic stem cell transplant recipients: A single‐center experience

Abstract

Introduction A high incidence of mortality and severe COVID‐19 infection was reported in hematopoietic stem cell transplant (HSCT) recipients during the early phases of the COVID‐19 pandemic; however, outcomes with subsequent severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants, such as the omicron variant, have yet to be reported. Additionally, rollout of COVID‐19 vaccinations in subsequent pandemic waves may modify COVID‐19 disease severity and mortality in this immunocompromised population. We describe COVID‐19 outcomes among a highly vaccinated population of HSCT recipients at a single center during successive waves of community transmission arising from the SARS‐CoV‐2 delta and omicron variants. Methods We retrospectively reviewed medical records of all HSCT recipients at our institution who tested positive for SARS‐CoV‐2 from May 2021 to May 2022. Descriptive statistics were reported; the chi‐square test was utilized to identify factors associated with 90‐day all‐cause mortality and severity of COVID‐19 infection. Results Over the 1‐year study period, 77 HSCT recipients at our center contracted COVID‐19 (43 allogenic; 34 autologous). Twenty‐six (33.8%) patients were infected with the SARS‐CoV‐2 delta variant, while 51 (66.2%) had the SARS‐CoV‐2 omicron variant. Thirty‐nine (50.6%) patients required hospitalization. More than 80% had received prior COVID‐19 vaccination (57.1% with two doses, 27.3% with three doses). The majority (90.9%) had mild disease; only one (1.3%) patient required mechanical ventilation. Active hematological disease at time of COVID‐19 infection was associated with increased odds of mortality [odds ratio (OR) = 6.90, 95% confidence interval (CI) = 1.20–40]. The 90‐day all‐cause mortality was 7.8% (six patients). Infection with the omicron variant (vs. delta) was associated with less severe illness (OR = 0.05, 95% CI = 0.01–0.47) and decreased odds of mortality (OR = 0.08, 95% CI = 0.01–0.76). Being on immunosuppression (OR = 5.10, 95% CI = 1.10–23.60) and being unvaccinated at disease onset (OR = 14.76, 95% CI = 2.89–75.4) were associated with greater severity of COVID‐19 infection. Conclusion We observed favorable outcomes with COVID‐19 infection in a cohort of vaccinated HSCT patients. The SARS‐CoV‐2 omicron variant was associated with both less severe illness and decreased odds of mortality. As COVID‐19 moves toward endemicity, early access to treatment and encouraging vaccination uptake is crucial in mitigating the challenge of COVID‐19 management among HSCT recipients. Surveillance and assessment of clinical outcomes with new SARS‐CoV‐2 variants also remains important in this immunocompromised population.

COVID‐19 in hematopoietic stem‐cell transplant recipients: A systematic review and meta‐analysis of clinical characteristics and outcomes

“…COVID‐19 clinical characteristics, medication used, and lethality are reported in Table 3. From the studies that reported symptomatic rate 7,11,15,21–26 we found 79.4% of symptomatic disease ( n = 624/785, range: 50.0% 26 to 100% 15,23 ). The hospitalization rate varied from 9.2% 26 to 74.0% 10 and the median duration of hospital stay from 14 7 to 8 11 days.…”

“…The most frequent hematological underline disease was acute myeloid leukemia in eight (50.0%) articles 7,10,15,19,22,23,25,26 . Allogeneic HSCT patients were the majority in most studies, 7,10,15,18,19,21–26 with a total of 861 patients (72.5%).…”

“…Tan et al., 15 in 1 year of observation, found 77 HSCT recipients with COVID‐19 in his service in Singapore. More than 84.4% were fully vaccinated (the authors considered ≥2 mRNA vaccine doses).…”

Response to mRNA SARS‐CoV‐2 vaccination evaluated by B‐cell receptor repertoire after tixagevimab/cilgavimab administration

“…Haematologists suggest that these patients should maintain multi‐modal prevention, such as infection‐prevention behaviours, vaccination and an antiviral antibody drug 1 . A study reported positive outcomes in a cohort of highly vaccinated HSCT recipients with COVID‐19 caused by the omicron variant as well as previous strains 15 …”

“…1 A study reported positive outcomes in a cohort of highly vaccinated HSCT recipients with COVID-19 caused by the omicron variant as well as previous strains. 15 Immunogenicity after SARS-CoV-2 vaccination, especially humoral immunity, is generally assessed by enzyme-linked immunosorbent assay (ELISA) using an anti-SARS-CoV-2 spike IgG antibody. 16 To date, the reactivity of vaccination has been evaluated by the measurement of antibody titers after vaccination in both healthy individuals and also in patients with various immune states, such as cancer patients.…”