Laboratoire de Virologie, Institut des Agents Infectieux, Centre National de Référence des virus des infections respiratoires, Hospices Civils de Lyon, Lyon, France.
ECDC Fellowship Programme, Public Health Microbiology Path (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Solna, Sweden.
J Med Virol. 2023 Aug;95(8):e28984. doi: 10.1002/jmv.28984.
We aimed to evaluate the association between the humoral and cellular immune responses and symptomatic SARS-CoV-2 infection with Delta or Omicron BA.1 variants in fully vaccinated outpatients. Anti-receptor binding domain (RBD) IgG levels and interferon-gamma (IFN-γ) release were evaluated at PCR-diagnosis of SARS-CoV-2 in 636 samples from negative and positive patients during Delta and Omicron BA.1 periods. Median levels of anti-RBD IgG in positive patients were significantly lower than in negative patients for both variants (p < 0.05). The frequency of Omicron BA.1 infection in patients with anti-RBD IgG concentrations ≥1000 binding antibody units (BAU)/mL was 51.0% and decreased to 34.4% in patients with concentrations ≥3000 BAU/mL. For Delta infection, the frequency of infection was significantly lower when applying the same anti-RBD IgG thresholds (13.3% and 5.3% respectively, p < 0.05). In addition, individuals in the hybrid immunity group had a 4.5 times lower risk of Delta infection compared to the homologous vaccination group (aOR = 0.22, 95% CI: [0.05-0.64]. No significant decrease in the risk of Omicron BA.1 infection was observed in the hybrid group compared to the homologous group, but the risk decreased within the hybrid group as anti-RBD IgG titers increased (aOR = 0.08, 95% CI: [0.01-0.41], p = 0.008). IFN-γ release post-SARS-CoV-2 peptide stimulation was not different between samples from patients infected (either with Delta or Omicron BA.1 variant) or not (p > 0.05). Our results show that high circulating levels of anti-RBD IgG and hybrid immunity were independently associated with a lower risk of symptomatic SARS-CoV-2 infection in outpatients with differences according to the infecting variant (www.clinicaltrials.gov; ID NCT05060939).
我们旨在评估体液和细胞免疫应答与完全接种疫苗的门诊患者中 Delta 或 Omicron BA.1 变异株引起的有症状 SARS-CoV-2 感染之间的关联。在 Delta 和 Omicron BA.1 期间，对 636 份 PCR 诊断为 SARS-CoV-2 的阴性和阳性患者样本进行了受体结合域（RBD）IgG 水平和干扰素-γ（IFN-γ）释放评估。对于两种变体，阳性患者的抗 RBD IgG 中位水平明显低于阴性患者（p<0.05）。在抗 RBD IgG 浓度≥1000 结合抗体单位（BAU）/mL 的患者中，Omicron BA.1 感染的频率为 51.0%，在浓度≥3000 BAU/mL 的患者中降至 34.4%。对于 Delta 感染，当应用相同的抗 RBD IgG 阈值时，感染的频率显著降低（分别为 13.3%和 5.3%，p<0.05）。此外，与同源疫苗接种组相比，混合免疫组感染 Delta 的风险降低了 4.5 倍（aOR=0.22，95%CI：[0.05-0.64]）。与同源组相比，混合组感染 Omicron BA.1 的风险未见明显降低，但随着抗 RBD IgG 滴度的增加，混合组的风险降低（aOR=0.08，95%CI：[0.01-0.41]，p=0.008）。在接受 SARS-CoV-2 肽刺激后，来自感染患者（无论是感染 Delta 还是 Omicron BA.1 变体）或未感染患者的样本之间 IFN-γ 释放无差异（p>0.05）。我们的结果表明，高循环水平的抗 RBD IgG 和混合免疫与门诊患者有症状 SARS-CoV-2 感染风险降低独立相关，并且根据感染变体存在差异（www.clinicaltrials.gov；ID NCT05060939）。
