Instituto de Medicina Tropical de Sao Paulo, Faculdade de Medicina da Universidade de Sao Paulo, São Paulo, SP, Brazil; Departamento de Moléstias Infecciosas e Parasitarias da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil.
Instituto de Medicina Tropical de Sao Paulo, Faculdade de Medicina da Universidade de Sao Paulo, São Paulo, SP, Brazil; Faculdade de Medicina da Universidade Municipal de Sao Caetano do Sul, São Caetano, SP, Brazil.
Clinics (Sao Paulo). 2022 Jun 16;77:100068. doi: 10.1016/j.clinsp.2022.100068. eCollection 2022.
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.
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.
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.
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.
本研究旨在评估感染大流行初期占主导地位的 SARS-CoV-2 株或 Gamma 变异株诱导的中和抗体反应是否对奥密克戎变异株有效。
对从未接种过 SARS-CoV-2 疫苗、因感染 SARS-CoV-2 原始株或 Gamma 变异株而出现无需住院治疗的轻症或中度症状的 109 名个体的恢复期血清进行体外中和抗体活性检测，以评估其对原始株和奥密克戎变异株的中和抗体活性。
感染原始株后，分别有 56 份（93.3%）、45 份（77.6%）和 1 份（1.7%）血清样本对原始株、Gamma 变异株和奥密克戎变异株的中和抗体呈阳性。感染 Gamma 变异株后，分别有 43 份（87.8%）和 2 份（4.1%）血清样本对 Gamma 和奥密克戎变异株的中和抗体呈阳性。
感染 SARS-CoV-2 原始株或 Gamma 变异株引起的轻症或中度感染产生的中和抗体不能预防奥密克戎变异株。
