Lower response to BNT162b2 vaccine in patients with myelofibrosis compared to polycythemia vera and essential thrombocythemia

Pimpinelli, Fulvia; Marchesi, Francesco; Piaggio, Giulia; Giannarelli, Diana; Papa, Elena; Falcucci, Paolo; Spadea, Antonio; Pontone, Martina; Di Martino, Simona; Laquintana, Valentina; La Malfa, Antonia; Di Domenico, Enea Gino; Di Bella, Ornella; Falzone, Gianluca; Ensoli, Fabrizio; Vujovic, Branka; Morrone, Aldo; Ciliberto, Gennaro; Mengarelli, Andrea

In a population of 42 Philadelphia negative myeloproliferative neoplasm patients, all on systemic active treatment, the likelihood of responding to anti-SARS-CoV-2 BNT162b2 vaccine at 2 weeks after the second dose was significantly lower in the ten patients with myelofibrosis compared to the 32 with essential thrombocythemia (n = 17) and polycythemia vera (n = 15) grouped together, both in terms of neutralizing anti-SARS-CoV-2 IgG titers and seroprotection rates (32.47 AU/mL vs 217.97 AU/mL, p = 0.003 and 60% vs 93.8%, p = 0.021, respectively). Ruxolitinib, which was the ongoing treatment in five patients with myelofibrosis and three with polycythemia vera, may be implicated in reducing vaccine immunogenicity (p = 0.076), though large prospective study is needed to address this issue.