3D visualization of mutations in the spike protein of the Omicron variation. Left: overhead view. Right: lateral view. Mutations are suggested in red. They occur all over the spike protein however especially in the receptor binding domain (RBD) and in the area referred to as the N-terminal domain (NTD). Credit: © Institut Pasteur– Félix Rey
The Omicron version was identified for the very first time in South Africa in November 2021 and has since spread out to many nations. Preliminary epidemiological studies reveal that the Omicron variant is more transmissible than the currently dominant virus (the Delta variant). Scientists from the Institut Pasteur and the Vaccine Research Institute, in collaboration with KU Leuven (Leuven, Belgium), Orléans Regional Hospital, Hôpital Européen Georges Pompidou (AP-HP), Inserm and the CNRS, studied the level of sensitivity of the Omicron version to monoclonal antibodies used in medical practice to prevent serious forms of the illness in individuals at threat, as well as to antibodies in the blood of people previously infected with SARS-CoV-2 or immunized.
Initial epidemiological studies show that the Omicron version is more transmissible than the Delta version. The Omicron variants biological qualities are still reasonably unknown. It has more than 32 mutations in the spike protein compared with the very first SARS-CoV-2 and was designated as a variant of concern by WHO on November 26, 2021.
In South Africa, the Omicron variant changed the other infections within a few weeks and caused a sharp increase in the number of cases detected. Analyses in different nations indicate that the doubling time for cases is roughly 2 to 4 days. Omicron has been found in lots of countries, including France and ended up being dominant by the end of 2021.
In a brand-new research study supported by the European Unions Health Emergency Preparedness and Response Authority (HERA), scientists from the Institut Pasteur and the Vaccine Research Institute, in partnership with KU Leuven (Leuven, Belgium), Orléans Regional Hospital, Hôpital Européen Georges Pompidou (AP-HP) and Inserm, studied the level of sensitivity of Omicron to antibodies compared with the presently dominant Delta variation. The aim of the study was to characterize the effectiveness of therapeutic antibodies, along with antibodies developed by individuals formerly contaminated with SARS-CoV-2 or immunized, in neutralizing this new version.
The researchers from KU Leuven isolated the Omicron variation of SARS-CoV-2 from a nasal sample of a 32-year-old woman who developed moderate COVID-19 a few days after returning from Egypt. The isolated virus was right away sent out to researchers at the Institut Pasteur, where healing monoclonal antibodies and serum samples from individuals who had actually been immunized or formerly exposed to SARS-CoV-2 were utilized to study the level of sensitivity of the Omicron variation.
The scientists utilized quick neutralization assays, established by the Institut Pasteurs Virus and Immunity Unit, on the separated sample of the Omicron virus. This collective multidisciplinary effort also included the Institut Pasteurs virologists and experts in the analysis of viral evolution and protein structure, together with teams from Orléans Regional Hospital and Hôpital Européen Georges Pompidou in Paris.
Six antibodies lost all antiviral activity, and the other 3 were 3 to 80 times less efficient versus Omicron than against Delta. The antibodies Bamlanivimab/Etesevimab (a combination established by Lilly), Casirivimab/Imdevimab (a mix established by Roche and understood as Ronapreve) and Regdanvimab (developed by Celtrion) no longer had any antiviral result versus Omicron.
” We demonstrated that this extremely transmissible version has obtained considerable resistance to antibodies. Many of the healing monoclonal antibodies presently available against SARS-CoV-2 are non-active,” remarks Olivier Schwartz, co-last author of the study and Head of the Virus and Immunity Unit at the Institut Pasteur.
The researchers observed that the blood of patients previously infected with COVID-19, gathered up to 12 months after symptoms, and that of individuals who had gotten two dosages of the Pfizer or AstraZeneca vaccine, taken 5 months after vaccination, hardly neutralized the Omicron variant. 5 to 31 times more antibodies were nevertheless required to reduce the effects of Omicron, compared with Delta, in cell culture assays.
” We now need to study the length of defense of the booster dosage. The vaccines probably become less reliable in providing security against contracting the infection, however they must continue to safeguard versus serious forms,” explains Olivier Schwartz.
” This research study shows that the Omicron variant hampers the efficiency of vaccines and monoclonal antibodies, but it likewise shows the capability of European scientists to work together to recognize obstacles and possible solutions. While KU Leuven was able to explain the first case of Omicron infection in Europe using the Belgian genome security system, our collaboration with the Institut Pasteur in Paris enabled us to carry out this research study in record time. There is still a good deal of work to do, but thanks to the assistance of the European Unions Health Emergency Preparedness and Response Authority (HERA), we have plainly now reached a point where researchers from the very best centers can operate in synergy and move towards a better understanding and more effective management of the pandemic,” remarks Emmanuel André, co-last author of the study, a Professor of Medicine at KU Leuven (Katholieke Universiteit Leuven) and Head of the National Reference Laboratory and the genome monitoring network for COVID-19 in Belgium.
The researchers concluded that the lots of anomalies in the spike protein of the Omicron variant enabled it to mainly evade the immune action. Continuous research study is being performed to figure out why this variant is more transmissible from one person to the next and to evaluate the long-lasting effectiveness of a booster dosage.
Reference: “Considerable escape of SARS-CoV-2 Omicron to antibody neutralization” by Delphine Planas, Nell Saunders, Piet Maes, Florence Guivel-Benhassine, Cyril Planchais, Julian Buchrieser, William-Henry Bolland, Françoise Porrot, Isabelle Staropoli, Frederic Lemoine, Hélène Péré, David Veyer, Julien Puech, Julien Rodary, Guy Baela, Simon Dellicour, Joren Raymenants, Sarah Gorissen, Caspar Geenen, Bert Vanmechelen, Tony Wawina-Bokalanga, Joan Martí-Carrerasi, Lize Cuypers, Aymeric Sève, Laurent Hocqueloux, Thierry Prazuck, Félix Rey, Etienne Simon-Lorrière, Timothée Bruel, Hugo Mouquet, Emmanuel André and Olivier Schwartz, 23 December 2021, Nature.DOI: 10.1038/ d41586-021-03827-2bioRxiv.
Preliminary epidemiological studies show that the Omicron version is more transmissible than the currently dominant infection (the Delta version). Scientists from the Institut Pasteur and the Vaccine Research Institute, in partnership with KU Leuven (Leuven, Belgium), Orléans Regional Hospital, Hôpital Européen Georges Pompidou (AP-HP), Inserm and the CNRS, studied the sensitivity of the Omicron variant to monoclonal antibodies utilized in scientific practice to prevent serious forms of the disease in people at threat, as well as to antibodies in the blood of individuals previously contaminated with SARS-CoV-2 or vaccinated. Initial epidemiological research studies show that the Omicron variant is more transmissible than the Delta version. The researchers observed that the blood of clients formerly infected with COVID-19, collected up to 12 months after symptoms, and that of people who had actually gotten 2 doses of the Pfizer or AstraZeneca vaccine, taken 5 months after vaccination, hardly reduced the effects of the Omicron variation.” This study shows that the Omicron variant hampers the effectiveness of vaccines and monoclonal antibodies, but it also demonstrates the capability of European researchers to work together to identify obstacles and potential options.
