Muñoz-Gómez, María JoséRyan, PabloQuero-Delgado, MartaMartin-Vicente, MariaCuevas, GuillermoValencia, JorgeJiménez, EvaBlanca-López, NataliaLara-Álvarez, Miguel ÁngelHernández-Rivas, José ÁngelRedondo, GerardoMas-Lloret, VicenteSepulveda-Crespo, DanielVazquez-Alcaraz, MonicaTorres-Macho, JuanMartinez, IsidoroResino, Salvador2024-06-282024-06-282024-07J Infect Public Health. 2024 Jul;17(7):102473.http://hdl.handle.net/20.500.12105/19881Background: Cancer patients often have weakened immune systems, resulting in a lower response to vaccines, especially those receiving immunosuppressive oncological treatment (OT). We aimed to assess the impact of OT on the humoral and T-cell response to the B.1 lineage and Omicron variant following COVID-19 vaccination in patients with solid and hematological neoplasms. Methods: We conducted a prospective study on cancer patients, stratified into OT and non-OT groups, who received a two-dose series of the COVID-19 mRNA vaccine and a booster six months later. The outcomes measured were the humoral (anti-SARS-CoV-2 S IgG titers and ACE2-S interaction inhibition capacity) and cellular (SARS-CoV-2 S-specific T-cell spots per million PBMCs) responses against the B.1 lineage and Omicron variant. These responses were evaluated four weeks after the second dose (n = 98) and eight weeks after the booster dose (n = 71). Results: The humoral response after the second vaccine dose against the B.1 lineage and Omicron variant was significantly weaker in the OT group compared to the non-OT group (q-value<0.05). A booster dose of the mRNA-1273 vaccine significantly improved the humoral response in the OT group, making it comparable to the non-OT group. The mRNA-1273 vaccine, designed for the original Wuhan strain, elicited a weaker humoral response against the Omicron variant compared to the B.1 lineage, regardless of oncological treatment or vaccine dose. In contrast, T-cell responses against SARS-CoV-2, including the Omicron variant, were already present after the second vaccine dose and were not significantly affected by oncological treatments. Conclusions: Cancer patients, particularly those receiving immunosuppressive oncological treatments, should require booster doses and adapted COVID-19 vaccines for new SARS-CoV-2 variants like Omicron. Future studies should evaluate the durability of the immune response and the efficacy of individualized regimens.engVoRSARS-CoV-2COVID-19 vaccineImmune responsesB.1 lineageOmicron variantCOVID-19COVID-19 VaccinesSpike Glycoprotein, CoronavirusSARS-CoV-2NeoplasmsAntibodies, ViralHumansProspective StudiesMaleFemaleMiddle AgedAgedT-LymphocytesImmunization, SecondaryVaccinationAdultImmunity, HumoralImmunoglobulin GImmunocompromised HostImmunity, CellularAttribution-NonCommercial-NoDerivatives 4.0 Internacional3886577417710247310.1016/j.jiph.2024.1024731876-035XJournal of infection and public healthopen access