H1N1 Influenza among Hematological Patients: Monocentric Influenza Cases from 2011 to 2016

We read with interest the paper by La Torre et al.,1 which conducted two systematic reviews and a meta-analysis to summarize the results of scientific works about influenza and pneumococcal vaccines in oncohematological patients. We paid specific attention to influenza vaccine results. The protection rate of H1N1 vaccine resulted in 31% and 30% after the first dose and booster dose, respectively. Protection rate of H3N2 and influenza B first dose was 42.6% and 39.6%, respectively. Considering the response rate, the pooled prevalence for H1N1 was 30% and 35% after the first dose and booster dose, respectively. The response rate for H3N2 was 21.7% after first dose and 24% after booster dose. Finally, the response rate for influenza B was 23.6% after the first dose and 29% after booster dose. Only a minority of patients experienced adverse events, most of them were mild and did not require treatment. Even though influenza vaccine elicits a low response rate among oncohematological patients, particularly in those who received transplantation, splenectomy or rituximab, it is an inexpensive intervention with few side effects. However, the first vaccine dose induces a small response, and the booster dose induces additional antibodies.