Department of Pathology, University Hospitals Cleveland Medical Center, Case Western Reserve University, School of Medicine, Cleveland, Ohio, USA.
College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio, USA.
Microbiol Spectr. 2024 Oct 3;12(10):e0060524. doi: 10.1128/spectrum.00605-24. Epub 2024 Aug 20.
This study aims to investigate humoral immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and assess the impact of booster vaccines. We recruited individuals scheduled to receive either the first (original formula) or the second (bivalent) booster following the initial two-dose SARS-CoV-2 vaccination. We tested for IgG antibodies targeting the spike protein receptor-binding domain (RBD), S1, S2, and nucleocapsid protein, as well as for neutralizing antibodies against Omicron BA.2, before and 14-28 days after receiving the boosters. One year after receiving the initial series of vaccinations, all participants maintained anti-RBD/S1 antibodies. However, levels were lower in individuals who were vaccinated only compared to those who had both vaccination and prior infection (hybrid immunity). Participants with hybrid immunity also showed higher retention of neutralizing antibodies (93% compared to 24% in vaccine-only individuals). Even before receiving any booster shots, participants with hybrid immunity had antibody levels similar to those of vaccine-only individuals after their first booster. After receiving booster shots, antibody levels at 14-28 days were similar regardless of the number of boosters or the type of immunity. About 1 year after the first booster, all participants maintained neutralizing antibodies, and vaccine-only individuals retained about 10 times higher levels of binding antibodies than those without a booster. Humoral immunity varies widely among individuals, and vaccination planning should consider both vaccination and infection history. Boosters are beneficial for increasing antibody levels to ensure sufficient protection against infection and helping bridge the immunity gap between vaccine-only and hybrid immunity.IMPORTANCEAs we move into the era of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine boosters and shifting from pandemic to endemic, the landscape has changed for both the circulating SARS-CoV-2 variants and population immunity. Even though recent waves of infection have been clinically milder than earlier variants due to the high levels of population immunity and the properties of the Omicron subvariants, vaccination remains crucial for managing COVID-19 in the post-pandemic era. Our study unveils significant variations in the retention of anti-SARS-CoV-2 binding antibody profiles and neutralizing antibody levels 1 year after the primary and the first booster mRNA vaccination. It adds new information regarding how boosters change antibody levels and durability in individuals with hybrid (vaccination plus infection) or vaccine-only (never-infected) immunity. The findings can shed light on future vaccination planning.
本研究旨在探究针对严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的体液免疫，并评估加强针疫苗的效果。我们招募了计划接种初始两剂 SARS-CoV-2 疫苗后的第一针（原始配方）或第二针（二价）加强针的个体。我们在接种加强针前后检测了针对刺突蛋白受体结合域（RBD）、S1、S2 和核衣壳蛋白的 IgG 抗体，以及针对奥密克戎 BA.2 的中和抗体。在初始系列疫苗接种一年后，所有参与者均保持针对 RBD/S1 的抗体。然而，与仅接种疫苗相比，同时接种疫苗和既往感染的个体（混合免疫）的抗体水平较低。混合免疫个体的中和抗体保留率也更高（与仅接种疫苗的个体相比，分别为 93%和 24%）。甚至在接种任何加强针之前，具有混合免疫的个体在接种第一针加强针后，其抗体水平与仅接种疫苗的个体相似。在接种加强针后，14-28 天时的抗体水平与加强针次数或免疫类型无关。在第一针加强针接种约 1 年后，所有参与者均保持中和抗体，仅接种疫苗的个体保留的结合抗体水平比未接种加强针的个体高约 10 倍。个体间的体液免疫差异很大，疫苗接种计划应同时考虑接种和感染史。加强针可提高抗体水平，确保对感染有足够的保护，并有助于弥合仅接种疫苗和混合免疫个体之间的免疫差距。
随着严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）疫苗加强针的推出，以及从大流行向地方病的转变，循环 SARS-CoV-2 变体和人群免疫的情况都发生了变化。尽管由于人群免疫力高和奥密克戎亚变体的特性，最近的感染浪潮在临床方面比早期变体更为温和，但疫苗接种在大流行后时期管理 COVID-19 方面仍然至关重要。我们的研究揭示了在初始和第一针 mRNA 疫苗接种后 1 年，针对 SARS-CoV-2 结合抗体谱和中和抗体水平的保留情况在个体间存在显著差异。它提供了有关加强针如何改变混合免疫（接种加感染）或仅接种疫苗（从未感染）个体的抗体水平和耐久性的新信息。这些发现可以为未来的疫苗接种计划提供参考。
