Out of the 158 monoclonal antibodies that were produced and tested, only 18%, 22%, 17%, 23%, and 18% remained active against BA.1, BA.2, BA.1.1, BA.2.12.1, and both BA.4 and BA.5, respectively.
Additionally, 43-73% of vaccinated individuals exhibited neutralizing activity against Omicron following two doses of the Pfizer-BioNTech BNT162b2 COVID-19 vaccine. Notably, booster immunization led to increased activity against all the Omicron sublineages. The neutralizing activity against BA.4 and BA.5 was low as compared to that against BA.1.1, BA.1, and BA.2 among vaccinated individuals.
مطالعه حاضر شامل جمعآوری نمونههای سرمی از افراد در حال نقاهت بیماری کروناویروس 2019 (COVID-19) بین آوریل و می 2020 بود. مطالعه [articipants were followed up for the analysis of long-term immunity to SARS-CoV-2, with additional serum samples collected after booster immunization between May and August 2021. Serum samples were also collected from vaccinated individuals after completing the initial immunization regimen, as well as after receiving booster doses.
Serum neutralizing activity was observed for samples that were collected at a median of 48 days post-infection with the ancestral SARS-CoV-2 strain. However, neutralizing activity was detectable in 0-15% of samples for BA.1 and BA1.1, while the activity was 45-50% for BA.2, BA.2.12.1, and BA.4/ 5. Booster immunization led to neutralizing activity against all the Omicron sublineages.
Slight variations in amino acid sequences of the antibodies were found to impact Omicron resistance and neutralization. The newly identified Omicron sublineages were also found to be able to escape from most monoclonal antibodies that were in clinical use. Bebtelovimab, along with R200-1F9, R568-1G9, and R207-2F11 antibodies, exhibited neutralizing activity against all Omicron sublineages.
Conclusions
اکثر مطالعات در مورد مقاومت نوع Omicron به خنثی سازی با واسطه آنتی بادی به سویه اولیه BA.1 Omicron محدود شده است. با این حال، چندین زیردین از Omicron متعاقباً ظهور کردند و نرخ عفونت را بیشتر افزایش دادند. بنابراین، تعیین خواص فرار آنتی بادی این زیر متغیرهای Omicron برای توسعه مداخلات پیشگیرانه و درمانی موثر مهم است.
ظهور سندرم حاد تنفسی ویروس کرونا 2 (SARS-CoV-2) نوع Omicron به سرعت منجر به افزایش نرخ عفونت در سطح جهان شد، علیرغم سطوح بالای محافظت در برابر SARS-CoV-2 توسط عفونت طبیعی و واکسیناسیون. یک پروتئین سنبله به شدت جهش یافته مسئول قابلیت انتقال بالای این نوع و قابلیت های فرار ایمنی است.
اگرچه فواصل دوز طولانی واکسن و دوزهای تقویت کننده در برابر سویه اجدادی SARS-CoV-2 تا حدی سطح محافظت در برابر نوع Omicron را فراهم می کند، تیتر آنتی بادی خنثی کننده در برابر این نوع در مقایسه با انواع دیگر بسیار کمتر است. به نظر می رسد چندین آنتی بادی مونوکلونال درمانی نیز در برابر عفونت های Omicron بی اثر باشند.
BA.2.12.1, BA.4, and BA.5 pseudoviruses were produced using an expression plasmid followed by the production of monoclonal antibodies. Thereafter, pseudovirus neutralization assays were conducted, along with an analysis of antibody amino acid sequences.
The spike amino acid changes relative to the wild-type SARS-CoV-2 spike protein were visualized using cryo-electron microscopy. The frequency of variant distribution was also analyzed.
Study findings
یک جدید میزبان سلولی و میکروب مطالعه خنثیسازی با واسطه آنتیبادی را در هر دو سطح مونوکلونال و پلی کلونال نشان میدهد.
در مورد مطالعه
مطالعه: زیرشاخه های SARS-CoV-2 Omicron الگوهای فرار آنتی بادی مشخصی را نشان می دهند. اعتبار تصویر: MarieGrecha / Shutterstock.com
زمینه
The current study demonstrates that Omicron sublineages are capable of escaping neutralization from both vaccination and previous infection and were resistant to many monoclonal antibodies. Taken together, genomic surveillance, along with sensitivity assessments, are important for monitoring the constant evolution of SARS-CoV-2 and determining appropriate therapeutic and prophylactic measures.
Journal reference:
- Gruell, H., Vanshylla, K., Korenkov, M., et al. (2022). SARS-CoV-2 Omicron sublineages exhibit distinct antibody escape patterns. Cell Host and Microbe. doi:10.1016/j.chom.2022.07.002.
The BA.1 spike protein contains 39 different amino acid residues as compared to the ancestral SARS-CoV-2 strain. Although other Omicron sublineages shared several mutations with BA.1, they also consisted of various unique mutations. Although the BA.1/BA.2 sublineages were responsible for the first Omicron wave, they were rapidly outcompeted by the BA.4 and BA.5 sublineages.