Efficacy and safety profile of COVID-19 mRNA vaccine in patients with hematological malignancies: Systematic review and meta-analysis

Abstract

Patient populations, including those with hematological malignancies, have different responses to COVID-19 vaccines. This study aimed to quantitatively analyze the efficacy and safety of COVID-19 mRNA vaccines in patients with hematological malignancies. Studies reporting on the efficacy and safety of COVID-19 mRNA vaccines in cohorts with hematological malignancies compared to healthy controls were systematically searched in four databases. Meta-analysis and subgroup analyses were performed to generate quantitative synthesis. Fifteen studies with 2,055 cohorts with hematological malignancies and 1,105 healthy subjects as control were included. After two doses of COVID-19 vaccination, only 60% of cohorts with hematological malignancies were seroconverted compared to healthy controls (RR 0.60; 95%CI 0.50–0.71). A single dose of the vaccine resulted in a significantly lower seroconversion rate (RR 0.30; 95%CI 0.16–0.54). Non-Hodgkin lymphoma cohorts had the lowest rate of seroconversion (RR 0.5; 95%CI 0.35–0.71) and those who received active treatments had lower immunological responses (RR 0.59; 95%CI 0.46–0.75). Antibody titers were lower in cohorts with hematological malignancies without any differences in adverse effects in both groups. In conclusion, cohorts with hematological malignancies showed a lower seroconversion rate and antibody titers after receiving COVID-19 mRNA vaccines. The type of malignancy and the status of treatment had a significant impact on the response to vaccination. The vaccines were shown to be safe for both patients with hematological malignancies and healthy controls. Booster doses and stricter health protocols might be beneficial for patient populations.

Oral anti‐viral therapy for early COVID‐19 infection in patients with haematological malignancies: A multicentre prospective cohort

“…Vaccination with three–four doses and to a lesser extent with two doses was protective against this event. These results are in line with previous evidence on HM patients who could benefit from additional doses of vaccine in the development of a more effective humoral and T‐cell‐mediated immune response 3–5,24–26 . Moreover, our study confirmed that viral shedding in these patients can be prolonged, especially in elderly patients and in those treated for NHL and CLL.…”

Clinical and Serological Follow-Up of 216 Patients with Hematological Malignancies after Vaccination with Pfizer-BioNT162b2 mRNA COVID-19 in a Real-World Study

“…Detectable B cells (at least 40/mm 3 ) and a long time since the last exposure to rituximab have been associated with the development of anti-SARS-CoV-2 spike protein antibodies after the booster vaccine [ 19 , 20 ]. Additional questions relate to the policy of vaccination against COVID-19, especially for patients with hematological malignancies who have shown a heterogeneous response to vaccination as mentioned in a recent meta-analysis and subgroup analyses [ 21 ]. According to the OnCovid registry, vaccination against SARS-CoV-2 was associated with a decrease in morbidity and mortality related to COVID-19 in cancer patients including 346 patients with hematological malignancies [ 22 ].…”

Real-world data on bio-clinical follow-up after vaccination with Pfizer-BioNT162b2 mRNA COVID-19 in 216 patients with hematological malignancies

“…Additional questions relate to the policy of vaccination against COVID-19, especially for patients with HM who have shown a heterogeneous response to vaccination as mentioned in a recent meta-analysis and subgroup analyses (17). According to the OnCovid registry, vaccination against SARSCoV-2 was associated with a decrease in morbidity and mortality related to COVID-19 in cancer patients including 346 patients with HM (18).…”