Boston University "creating a new deadly COVID-19"? In fact, normal scientific research achievements are distorted and misunderstood

Recently, a number of domestic and foreign media reported that researchers at Boston University in the United States combined Omicron with the original strain of COVID-19 to create a new type of COVID-19, which can kill 80% of infected mice.

This news caused widespread controversy around the world. Subsequently, Boston University responded, saying that these reports were "false and inaccurate". First of all, this study is not a gain of function study, that is, it does not amplify the risk of the original COVID-19-19 strain, but actually reduces the risk of virus replication. Secondly, these reports distort the purpose of this study, which is to determine the main determinants of the transmissibility and pathogenicity of COVID-19, so as to develop better and more targeted treatments to combat the COVID-19 epidemic.

In fact, this research of Boston University was published on the preprint website bioRxiv on October 14, 2022, and the paper was entitled: Role of spike in the pathetic and antigenic behavior of SARS CoV-2 BA 1 Omicron。

The author of the paper is from the Mohsan Saeed team of the National Emerging Infectious Diseases Laboratory (NEIDL) of Boston University. Let's take a look at what this research has done through this paper.

The national emerging infectious diseases laboratory (Neidl) of Boston University has been committed to studying the original strain of COVID-19 and Omicron, the main epidemic strain now. Compared with the original strain, the spike protein (S protein) of Omicron has a large number of variations, is highly infectious, and is more likely to escape from the vaccine, but its pathogenicity is greatly reduced. Most people infected with Omicron show no symptoms or only mild symptoms, which is unlikely to cause serious diseases.

Therefore, the research team wants to find out which parts of COVID-19 determine its infectivity and pathogenicity.

The research team combined Omicron with the original virus strain. Specifically, the S gene of Omicron was inserted into the genome of the original virus strain, so that a recombinant chimeric virus strain (Omi-S) with Omicron S protein on its surface was produced. The recombinant chimeric strain was compared with Omicron.

The experimental results showed that the new strain carrying Omicron S protein could effectively escape the vaccine induced humoral immunity (neutralizing antibody), mainly due to the mutation of its receptor binding motif (RBM).

In K18-hACE2 mice, Omicron will cause mild and non fatal infection, and the new strain carrying Omicron S protein will cause serious disease. The mortality of mice after infection is as high as 80%, while the mortality of mice after infection of the original strain is 100%.

These results showed that the escape of Omicron from the vaccine was determined by the mutation in its spike protein (S protein), and its pathogenicity was mainly determined by factors other than S protein. The research team said that identifying these proteins will help to better diagnose and treat COVID-19 infection.

In general, this study provided an important insight into the pathogenicity of Omicron. This study found that the S protein with the most mutations in Omicron played some but not the main role in reducing the pathogenicity. In vitro infection experiments, the new strain carrying the S protein of Omicron had higher replication efficiency than Omicron. In K18-hACE2 mice, the new strain carrying Omicron S protein caused 80% of mice to die, which was in sharp contrast to the non lethal effect of Omicron, but was lower than the 100% lethal rate of the original strain to mice. This indicates that mutations other than S protein are the main determinants of the weakened pathogenicity of Omicron.

This study also showed that the mutation of receptor binding motif (RBM) in Omicron's S protein was the main determinant of humoral immunity (neutralizing antibody) induced by viral escape vaccine. The research team also found two mutation hot spots in RBM, one is E484A mutation, and the other includes Q493R, G496S, Q498R, N501Y and Y505H. They endow Omicron with the ability to escape neutralizing antibody.

Boston University said that the study was reviewed and approved by the Institutional Biosafety Committee, which is composed of scientists and local community members, and the Boston Public Health Committee also approved the study.

Boston University also said that this research will bring better and targeted COVID-19 treatment interventions, help fight against future epidemics, and thus bring benefits to the public.

Professor Lei Ruipeng, Executive Director of the Bioethics Research Center of Huazhong University of Science and Technology and a member of the WHO COVID-19 Ethics and Governance Expert Group, said to Bioworld that the research on this kind of synthetic virus with non functional gain done by Boston University is scientifically necessary, but it needs to standardize the process, strictly approve and supervise to prevent potential biosafety risks.

Reference material:

https://www.biorxiv.org/content/10.1101/2022.10.13.512134v1

https://www.nbcboston.com/news/local/boston-university-pushes-back-on-claims-of-new-deadly-covid-strain/2865815/