Researchers investigate the severity of post-infection disease with SARS-CoV-2 omicrons in blood patients

Patients with hematologic disease are at increased risk of morbidity and mortality after infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. It is currently unknown whether Omicron variants reduce the severity of such individual illnesses.

New research published in European Journal of Hematology Addressed this gap in our understanding by studying the clinical outcomes and spectra of 61 patients infected with the SARS-CoV-2 Omicron variant.

Background

Since the outbreak of Coronavirus Disease 2019 (COVID-19) in 2019, non-pharmaceutical interventions (NPIs), in addition to COVID-19 morbidity and mortality, have continued to disrupt daily life.

The disease is currently known to affect multiple systems such as the cardiovascular system, nervous system, and gastrointestinal tract.

Blood patients are exposed to immunosuppressive treatment and suffer from severe immunodeficiency. This makes such patients more vulnerable to the fatal consequences of being infected with SARS-CoV-2. Abnormal hemoglobinopathy, such as sickle cell disease (SCD) and transfusion-dependent beta-thalassemia (TDT), is associated with an increased risk of death.

Although morbidity and mortality aspects are well documented in blood patients, the clinical course of the disease in patients with non-malignant hematopoietic disease has not been well studied. Such patients have also been observed to be unresponsive to vaccination. A significant proportion of patients showed low antibody response even after three mRNA vaccine doses.

The Omicron variant is now the predominantly circulating strain of SARS-CoV-2, and its clinical manifestations are significantly different from previous variants. Although mortality has decreased, Omicron is less susceptible to being neutralized by treatment or vaccination with monoclonal antibodies. Because data on COVID-19 blood patients are rare, in the current study, scientists analyzed the disease characteristics of this highly vulnerable population.

Main survey results

Early data showed diminished disease severity with the Omicron mutant, but morbidity and mortality in blood patients remained high compared to the general population. The authors claim that this study is the first to explain the disease severity of the SARS-CoV-2 omicron variant in both outpatient and inpatient settings.

The sample size was as small as 61 individuals. During the study, 10 patients remained asymptomatic, and their proportions were observed to be similar to pre-Omicron and pre-vaccination era statistics. Most patients showed mild or moderate illness, and overall, 50 patients showed common symptoms of COVID-19. More specifically, 60.66% of patients reported fatigue, 52.46% reported cough, and 39.34 reported fever. Seven patients required oxygen therapy and 10 patients reported dyspnea. Anosmia and ageusia were observed in less than 10% of patients. No significant hemolysis was observed in patients suffering from hereditary hemolytic anemia.

The severity of the disease could be studied in 60 patients, and during the study period, 5 patients required ICU admission due to a serious illness. The mortality rate for this cohort of patients was 9.84, but there was heterogeneity in the causes of death. The mortality rate for non-malignant hematopoietic patients was 6.25%. The increased prevalence of comorbid pulmonary and cardiovascular disease may have made such individuals more susceptible to more serious clinical outcomes. It should also be noted that one patient who died was not vaccinated and the other five were exposed to B cell-oriented therapy prior to infection. However, as mentioned above, most blood patients remained asymptomatic or reported mild symptoms.

During the pandemic process, several treatment options have also emerged. Molnupiravir and solovimab have been approved for the treatment of outpatients in the at-risk category. In this study, 4 patients were treated with the former and 17 patients were treated with the latter. Only one person was admitted to the ICU after treatment, suggesting overall superior resistance to both drugs. Researchers have pointed out the urgent need to further evaluate virus-specific treatment in blood patients infected with SARS-CoV-2.

Closing words

The results taken together suggest a milder symptom of Omicron infection in blood patients compared to previous SARS-CoV-2 mutants. However, scientists cannot speculate whether these results are due to existing host immunity or changes in viral pathogenicity, and this issue will be considered in future large-scale studies. Said you need to.