Absence of neutralizing antibodies against the Omicron SARS-CoV-2 variant in convalescent sera from individuals infected with the ancestral SARS-CoV-2 virus or its Gamma variant

Abstract Objectives: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. Methods: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. Results: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. Conclusions: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant. HIGHLIGHTS Individuals previously infected with SARS-CoV-2 ancestral strain do not develop neutralizing antibodies against the Omicron variant. Omicron variant escapes immune response after SARS CoV-2 previous infection with the SARS CoV-2 Gamma variant. Individuals previously infected with SARS-CoV-2 ancestral strain or with SARS-CoV-2 Gamma variant will likely have little protection if subsequently exposed to the Omicron variant.

Disseminated Fusarium infection in autologous stem cell transplant recipient

Disseminated infection by Fusarium is a rare, frequently lethal condition in severely immunocompromised patients, including bone marrow transplant recipients. However, autologous bone marrow transplant recipients are not expected to be at high risk to develop fusariosis. We report a rare case of lethal disseminated Fusarium infection in an autologous bone marrow transplant recipient during pre-engraftment phase.

Estudo de fase II com doses fracionadas diárias de etoposide oral em pacientes com câncer de mama estádio IV refratário a múltiplos esquemas quimioterápicos / Phase II study of fractionated daily doses of oral etoposide in patients with stage IV breast cancer refractory to multiple chemotherapy regimens

O etoposide é um inibidor da topoisomerase II capaz de produzir respostas objetivas em cerca de 10% das pacientes com câncer de mama metastático após a falha a esquemas convencionais. A administração oral de doses fracionadas de etoposide produz um aumento significativo do tempo de exposição dos tecidos em níveis terapêuticos deste agente, aumentando o seu índice terapêutico. Neste artigo, são descritos os resultados de um ensaio clínico de fase II com etoposide oral em doses fracionadas diárias em 20 mulheres com câncer de mama metastático refratário a múltiplos esquemas quimioterápicos. Foram elegíveis pacientes entre 18-75 anos de idade, desempenho clínico entre 0-2 (ECOG), diagnóstico histopatológico de câncer de mama, doença metastática visceral, sem disfunção de órgãosvitais e sem envolvimento do Sistema Nervoso Central (SNC). A assinatura de um documento de consentimento pelapaciente, segundo as normas da CONEP e do Comitê de Ética da Instituição, era condição necessária para inclusão.O conteúdo da ampola de etoposide para uso endovenoso foi administrado por via oral na dose de 20mg/m2 a cadaoito horas, diluído em veículo ácido (suco de laranja ou uva), diariamente por 14 dias, seguido de sete dias deintervalo. A cada 21 dias, as pacientes foram reavaliadas quanto à toxicidade (critério do NCI-CTC) e, a cada doisciclos (42 dias), quanto à resposta tumoral (critério da RECIST). As pacientes foram tratadas até a progressão, toxicidade limitante ou desejo próprio de interromper o tratamento. Foram incluídas 20 pacientes no estudo, tendo sido analisado um total de 55 ciclos de tratamento, com uma mediana de dois ciclos por paciente (1-10). Os efeitosadversos mais observados foram: náusea (36%), vômitos (24%), mucosite (16%) e neutropenia (14%). Neutropenia febril ocorreu em apenas um caso (2%). Não foram documentadas respostas objetivas. Entretanto, 9 pacientes apresentaram doença estável (45%), algumas com duração prolongada (30+, 21+ e...

Etoposide is an inhibitor of the nuclear topoisomerase II enzyme, which produces objective tumor responses inabout 10% of patients with metastatic breast cancer failing to standard chemotherapy regimens. Fractionatedoral administration of etoposide causes significant increase in tissue drug exposure, leading to a better therapeuticindex. In this paper, the outcomes of a Phase II trial of fractionated oral daily doses of etoposide conducted in20 women with metastatic breast cancer, who progressed following multiple chemotherapy regimens, are described. Eligible patients were those between 18-75 years old, ECOG performance status between 0-2, confirmed histopathological diagnosis of breast cancer, presence of visceral involvement, no vital organs dysfunction and no CNS involvement. A written informed consent was required, in accordance with the local IRB and theMinistry of Health of Brazil. The content of an ampoule for IV use was administered orally, at the dose of 20mg/m2, every eight hours, diluted in a low pH fluid (orange or grape juice), daily for 14 consecutive days,followed by a 7-day rest. Patients were reviewed every 21 days for toxicity (NCI-CTC criteria), and every 42days for tumoral response (RECIST criteria). Patients were treated until tumor progression, dose-limiting toxicityor own desire to interrupt the treatment. Twenty patients were included in the trial, and a total of 55 treatment cycles administered with a median of two cycles per patient (1-10) was evaluated. The most common side-effects were nausea (36%), vomiting (24%), mucositis (16%) and neutropenia (14%). Febrile neutropenia was documented in one case (2%) only. No objective response was documented. However, nine patients showed stable disease (45%), in some cases with prolonged duration (30+, 21+ and 18 weeks). The median duration of stable disease was 15 weeks (9-30+). In summary, this daily fractionated regimen of oral etoposide was welltolerated, producing...