Low serologic response to COVID-19 vaccines in patients with hematologic malignancies may lead to a higher rate of infections with the novel coronavirus in this population, according to preliminary results from the EPICOVIDEHA survey published in Blood. The study shows that greater age appears to be the primary factor associated with COVID-19–related mortality, but despite this association, COVID-19 vaccination can substantially reduce mortality rates in these patients.
“The results obtained so far [from the EPICOVIDEHA survey] confirm the absolute effectiveness of the anti–COVID-19 vaccination in patients with hematologic malignancies, especially in myeloid diseases,” said lead study author Livio Pagano, MD, of Catholic University of the Sacred Heart in Rome, Italy.
Given the novelty of the coronavirus responsible for COVID-19, as well as the fast-tracked introduction of mRNA, inactive, and vector-based COVID-19 vaccines, few data exist to conclude whether the efficacy of COVID-19 vaccination is affected by hematologic comorbidities or the treatments used to manage these conditions.
Dr. Pagano explained that the “main problem is that patients with hematologic malignancies require immunosuppressive therapies, typically steroids and monoclonal antibodies, which, as already demonstrated in other studies, can limit the effectiveness of the vaccination campaign in [patients with] lymphomas, chronic lymphocytic leukemia, and myeloma.”
To understand the effects of COVID-19 vaccination in hematologic malignancies, Dr. Pagano and colleagues administered the EPICOVIDEHA survey to patients with hematologic malignancies who received vaccinations against COVID-19.
A total of 113 COVID-19 episodes in partially and fully vaccinated patients with hematologic malignancies had been registered as of the time of this study. Most of the cases were among men (61.1%) and those over the age of 50 (85.8%). The majority of patients (>80%) with COVID-19 episodes had underlying lymphoproliferative malignancies. Approximately 68.1% of patients (n=78) had received active therapy for their underlying malignancy at the time of COVID-19 infection or within the three months prior to infection onset.
The median duration from the last vaccine dose to COVID-19 diagnosis was 64 days. Most patients were fully vaccinated (77%), while the remaining patients had received only one shot. The group of fully vaccinated patients received a COVID-19 diagnosis more than two weeks after the second vaccine dose.
In 37 cases, the most frequently observed variant was the alpha variant. Among 40 fully vaccinated patients whose post-vaccine immunoglobulin G levels were measured, 32.5% (n=13) had an antibody response to the vaccine. The remaining 67.5% of patients (n=27) had either a critical or severe infection. Approximately 66.4% of patients (n=75) were hospitalized. Of those admitted to the hospital, 16 were admitted to an intensive care unit and 10 of these patients received mechanical ventilation.
The overall mortality rate was 12.4% (n=14) after a 30-day follow-up post COVID-19 diagnosis. The main or secondary cause of death in all but one patient was COVID-19. Regarding mortality, there was no significant difference between partially and fully vaccinated patients (15.4% vs. 11.5%, respectively; p=0.734) or those who achieved a serologic response to vaccine versus those who didn’t (13.3% vs. 15.6%; p=1).
In a multivariable analysis, age was the only factor independently associated with the risk of mortality in vaccinated patients (hazard ratio = 1.053; 95% CI 1.004-1.105; p=0.035). Nearly 72% of patients who died had underlying lymphoproliferative malignancies, and none had underlying acute myeloid leukemia.
A limitation of the study was its relatively small sample size. As of the end of January 2022, the research team’s ongoing research involved validating 700 cases, according to Dr. Pagano. An analysis of the first 400 cases indicated a mortality rate around 15%, he said. The hope is that future findings may offer more precise information that could hold greater clinical implications.
In terms of future directions, Dr. Pagano explained that an evaluation is underway to determine whether the use of anti–COVID-19 monoclonal antibodies can reduce the risk of death in patients with hematologic malignancies who, despite vaccination, develop infection with the novel coronavirus.
Any conflicts of interest declared by the authors can be found in the original article.
Reference
Pagano L, Salmanton-García J, Marchesi F, et al. COVID-19 in vaccinated adult patients with hematological malignancies. Preliminary results from EPICOVIDEHA [published online ahead of print, 2021 Nov 8]. Blood. doi: 10.1182/blood.2021014124.
