Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Kith Pradhan
Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, United States
Benjamin Duva
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Juan Manuel Carreno
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, United States; Center for Vaccine Research and Pandemic Preparedness (C-VARPP), Icahn School of Medicine at Mount Sinai, New York, United States
Srabani Sahu
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Victor Thiruthuvanathan
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Sean Campbell
Department of Pathology, Montefiore Medical Center, Bronx, United States
Sonia Gallego
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Tushar D Bhagat
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Johanna Rivera
Department of Medicine, Albert Einstein College of Medicine, Bronx, United States
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Raul Olea
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Maite Sabalza
Euroimmun, Mountain Lakes, United States
Lauren C Shapiro
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Matthew Lee
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Ryann Quinn
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Ioannis Mantzaris
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Edward Chu
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Britta Will
Department of Oncology, Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, United States
Liise-anne Pirofski
Department of Medicine, Albert Einstein College of Medicine, Bronx, United States
Florian Krammer
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, United States; Center for Vaccine Research and Pandemic Preparedness (C-VARPP), Icahn School of Medicine at Mount Sinai, New York, United States; Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, United States
Background: Cancer patients show increased morbidity with COVID-19 and need effective immunization strategies. Many healthcare regulatory agencies recommend administering ‘booster’ doses of COVID-19 vaccines beyond the standard two-dose series, for this group of patients. Therefore, studying the efficacy of these additional vaccine doses against SARS-CoV-2 and variants of concern is of utmost importance in this immunocompromised patient population Methods: We conducted a prospective single arm clinical trial enrolling patients with cancer that had received two doses of mRNA or one dose of AD26.CoV2.S vaccine and administered a third dose of mRNA vaccine. We further enrolled patients that had no or low responses to three mRNA COVID vaccines and assessed the efficacy of a fourth dose of mRNA vaccine. Efficacy was assessed by changes in anti-spike antibody, T-cell activity, and neutralization activity, which were again assessed at baseline and 4 weeks. Results: We demonstrate that a third dose of COVID-19 vaccine leads to seroconversion in 57% of patients that were seronegative after primary vaccination series. The immune response is durable as assessed by anti-SARS-CoV-2 (anti-S) antibody titers, T-cell activity, and neutralization activity against wild-type (WT) SARS-CoV2 and BA1.1.529 at 6 months of follow-up. A subset of severely immunocompromised hematologic malignancy patients that were unable to mount an adequate immune response (titer <1000 AU/mL) after the third dose and were treated with a fourth dose in a prospective clinical trial which led to adequate immune boost in 67% of patients. Low baseline IgM levels and CD19 counts were associated with inadequate seroconversion. Booster doses induced limited neutralization activity against the Omicron variant. Conclusions: These results indicate that third dose of COVID vaccine induces durable immunity in cancer patients and an additional dose can further stimulate immunity in a subset of patients with inadequate response. Funding: Leukemia Lymphoma Society, National Cancer Institute. Clinical trial number: NCT05016622.