Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China.
NHC Key Laboratory of Research on Quality and Standardization of Biotech Products and NMPA Key Laboratory for Quality Research and Evaluation of Biological Products, WHO Collaborating Center for Standardization and Evaluation of Biologicals, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC), Beijing, China.
J Med Virol. 2023 Jan;95(1):e28279. doi: 10.1002/jmv.28279. Epub 2022 Nov 11.
The long-term protective efficacy of neutralizing antibodies (Nabs) against Omicron subvariants after inactivated booster vaccines remains elusive. During the follow-up study, 54 healthy volunteers aged 20-31 years received inactivated CoronaVac booster vaccinations and were monitored for 221 days. The dynamic efficacy and durability of Nab against Omicron subvariants BA.1, BA.2, BA.2.12.2, and BA4/5 were assessed using a pseudotyped virus neutralization assay at up to nine time points post immunization. The antibody response against Omicron subvariants was substantially weaker than D614G, with BA.4/5 being the least responsive. The geometric mean titer (GMT) of Nab against Omicron subvariants BA.1, BA.2, BA.2.12.1, and BA.4/5 was 2.2-, 1.7-, 1.8-, and 2.2-fold lower than that against D614G (p < 0.0001). The gap in Nab response between Omicron subvariants was pronounced during the 2 weeks-2 months following booster vaccination (p < 0.05). Seven months post booster, the antibody potency against D614G was maintained at 100% (50% for Nab titers ≥ 100 50% inhibitory dilution [EC ]), whereas at 77.3% for BA.1, 90.9% for BA.2, 86.4% for BA.2.12.1, and 86.4% for BA.4/5 (almost 20% for Nab titers ≥ 100 EC ). Despite the inevitable immune escape, Omicron subvariants maintained sustained and measurable antibody potency post-booster vaccination during long-term monitoring, which could help optimize immunization strategies.
在灭活疫苗加强针后，针对奥密克戎亚变种的中和抗体（Nabs）的长期保护效果仍然难以捉摸。在随访研究中，54 名年龄在 20-31 岁的健康志愿者接受了灭活科兴疫苗加强针，并监测了 221 天。通过在免疫后最多 9 个时间点使用假病毒中和测定法评估了针对奥密克戎亚变种 BA.1、BA.2、BA.2.12.2 和 BA4/5 的 Nab 的动态疗效和持久性。针对奥密克戎亚变种的抗体反应明显弱于 D614G，而 BA.4/5 的反应性最低。针对奥密克戎亚变种 BA.1、BA.2、BA.2.12.1 和 BA.4/5 的 Nab 几何平均滴度（GMT）分别比针对 D614G 低 2.2、1.7、1.8 和 2.2 倍（p<0.0001）。在加强针接种后 2 周到 2 个月内，Nab 对奥密克戎亚变种的反应差异显著（p<0.05）。加强针接种 7 个月后，针对 D614G 的抗体效力保持在 100%（针对 Nab 滴度≥10050%抑制稀释度[EC]的效力为 50%），而针对 BA.1 为 77.3%，针对 BA.2 为 90.9%，针对 BA.2.12.1 为 86.4%，针对 BA.4/5 为 86.4%（针对 Nab 滴度≥100 EC 的效力低近 20%）。尽管不可避免地发生了免疫逃逸，但奥密克戎亚变种在长期监测中在加强针接种后仍保持持续和可测量的抗体效力，这有助于优化免疫策略。
