<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">M Peeters</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">L Verbruggen</style></author><author><style face="normal" font="default" size="100%">L Teuwen</style></author><author><style face="normal" font="default" size="100%">G Vanhoutte</style></author><author><style face="normal" font="default" size="100%">S Raats</style></author><author><style face="normal" font="default" size="100%">Isolde Van der Massen</style></author><author><style face="normal" font="default" size="100%">Sigrid C.J. De Keersmaecker</style></author><author><style face="normal" font="default" size="100%">Y Debie</style></author><author><style face="normal" font="default" size="100%">S Anguille</style></author></secondary-authors><tertiary-authors><author><style face="normal" font="default" size="100%">S Vande Kerckhove</style></author><author><style face="normal" font="default" size="100%">I Desombere</style></author></tertiary-authors><subsidiary-authors><author><style face="normal" font="default" size="100%">B Peeters</style></author><author><style face="normal" font="default" size="100%">M Huizing</style></author><author><style face="normal" font="default" size="100%">Pieter Pannus</style></author><author><style face="normal" font="default" size="100%">K Neven</style></author><author><style face="normal" font="default" size="100%">K K Ariën</style></author><author><style face="normal" font="default" size="100%">G. A. Martens</style></author><author><style face="normal" font="default" size="100%">Marc Van den Bulcke</style></author><author><style face="normal" font="default" size="100%">E Roelant</style></author><author><style face="normal" font="default" size="100%">Maria Goossens</style></author><author><style face="normal" font="default" size="100%">T Vandamme</style></author><author><style face="normal" font="default" size="100%">P van Dam</style></author></subsidiary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Reduced humoral immune response after BNT162b2 coronavirus disease 2019 messenger RNA vaccination in cancer patients under antineoplastic treatment.</style></title><secondary-title><style face="normal" font="default" size="100%">ESMO Open</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antineoplastic Agents</style></keyword><keyword><style  face="normal" font="default" size="100%">BNT162 Vaccine</style></keyword><keyword><style  face="normal" font="default" size="100%">COVID-19</style></keyword><keyword><style  face="normal" font="default" size="100%">COVID-19 Vaccines</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Immunity, Humoral</style></keyword><keyword><style  face="normal" font="default" size="100%">Neoplasms</style></keyword><keyword><style  face="normal" font="default" size="100%">Prospective Studies</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Messenger</style></keyword><keyword><style  face="normal" font="default" size="100%">SARS-CoV-2</style></keyword><keyword><style  face="normal" font="default" size="100%">Vaccination</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2021 Oct</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">6</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;b&gt;BACKGROUND: &lt;/b&gt;Cancer patients are at a higher risk of developing severe coronavirus disease 2019 (COVID-19). However, the safety and efficacy of COVID-19 vaccination in cancer patients undergoing treatment remain unclear.&lt;/p&gt;

&lt;p&gt;&lt;b&gt;PATIENTS AND METHODS: &lt;/b&gt;In this interventional prospective multicohort study, priming and booster doses of the BNT162b2 COVID-19 vaccine were administered 21 days apart to solid tumor patients receiving chemotherapy, immunotherapy, targeted or hormonal therapy, and patients with a hematologic malignancy receiving rituximab or after allogeneic hematopoietic stem cell transplantation. Vaccine safety and efficacy (until 3 months post-booster) were assessed. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain (RBD) antibody levels were followed over time (until 28 days after the booster) and in&amp;nbsp;vitro SARS-CoV-2 50% neutralization titers (NT50) toward the wild-type Wuhan strain were analyzed 28 days after the booster.&lt;/p&gt;

&lt;p&gt;&lt;b&gt;RESULTS: &lt;/b&gt;Local and systemic adverse events (AEs) were mostly mild to moderate (only 1%-3% of patients experienced severe AEs). Local, but not systemic, AEs occurred more frequently after the booster dose. Twenty-eight days after the booster vaccination of 197 cancer patients, RBD-binding antibody titers and NT50 were lower in the chemotherapy group {234.05 IU/ml [95% confidence interval (CI) 122.10-448.66] and 24.54 (95% CI 14.50-41.52), respectively} compared with healthy individuals [1844.93 IU/ml (95% CI 1383.57-2460.14) and 122.63 (95% CI 76.85-195.67), respectively], irrespective of timing of vaccination during chemotherapy cycles. Extremely low antibody responses were seen in hematology patients receiving rituximab; only two patients had RBD-binding antibody titers necessary for 50% protection against symptomatic SARS-CoV-2 infection (&amp;lt;200 IU/ml) and only one had NT50 above the limit of detection. During the study period, five cancer patients tested positive for SARS-CoV-2 infection, including a case of severe COVID-19 in a patient receiving rituximab, resulting in a 2-week hospital admission.&lt;/p&gt;

&lt;p&gt;&lt;b&gt;CONCLUSION: &lt;/b&gt;The BNT162b2 vaccine is well-tolerated in cancer patients under active treatment. However, the antibody response of immunized cancer patients was delayed and diminished, mainly in patients receiving chemotherapy or rituximab, resulting in breakthrough infections.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue></record></records></xml>