Omicron: The worst mutation in the history of the new coronavirus?No need to panic, the sky can’t fall

The WHO held an emergency meeting and sounded the alarm to the world: the new coronavirus mutant strain B.1.1.529 was listed as a “mutant strain that needs attention” and named Omicron (Omicron). The World Health Organization pointed out that the Omi Keron mutant was reported for the first time in South Africa. Preliminary studies have shown that this mutant increases the risk of reinfecting the human body with the virus. Omicron is considered to be the most ferocious and worst mutated strain of the new crown in history. At present, many countries and regions, including the United Kingdom, the United States, Switzerland, and Hong Kong, have suspended multi-country routes to and from Africa including South Africa. Omicron is coming fiercely, and the upward trend and the unknown about the virus are spreading around the world.

What are the characteristics of Omicron (the latest mutant strain)? Why does it cause all parties to worry? The Omicron variant strain first appeared in South Africa. Professor Tulio de Oliveira, director of the South Africa Epidemic Response and Innovation Center, said at the press conference that the high number of mutations in the Omicron strain has led to a rebound in the South African epidemic. South Africa is one of the most severely affected countries in Africa. On November 25, there were 2465 new confirmed cases in the area, which is a surge of more than 20 times from the 106 in early November.

The National Institute for Communicable Diseases (NICD) of South Africa has sequenced its genome and, as of November 26, has recorded at least 77 confirmed cases of Omicron. Early polymerase chain reaction test results showed that 90% of the new local cases were caused by the new variant virus. South Africa has also been the place where other mutant strains were discovered in the past. In December 2020, the Beta strain first appeared in South Africa and then spread to nearly 70 countries. The Delta virus, which was first discovered in India, was introduced to South Africa in May this year, triggering a severe third wave of epidemics.

The cause of the unusually weird Omicron in South Africa is likely to be directly linked to the high prevalence of AIDS in the region. The HIV infection rate in South Africa exceeds 13% (total about 8 million people). The infection rate for women aged 15 to 49 is over 21%, and the infection rate for adult men of the same age is about 18%. Under the conditions of modern medicine, HIV infection does not mean suffering from AIDS (immune deficiency syndrome, AIDS), but the huge number of infections still causes nearly 4 million AIDS patients in South Africa.

According to the results of the meeting of the New Coronavirus Evolution Technical Advisory Group (TAG-VE) expert group, preliminary evidence shows that compared with other VOC variants (such as Delta), Omicron variants have increased transmission capacity. At present, this variant strain has been found in almost all provinces of South Africa, and the number of cases is increasing rapidly, and the variant strain is more likely to have a competitive advantage.

According to the spike protein of the Omicron (right) strain compared with the new coronavirus delta (left) strain, the Omicron strain has more spike protein mutations. These variations are diverse, and most of them are located in areas that interact with human cells.

The Omicron strain has attracted great attention because it contains more mutations than the Delta strain (only 16 mutations) that ravages the world. The Omicron strain contains more than 50 mutations, of which there are 32 mutations on the spike protein alone. The spike protein can help the new coronavirus to bind to and invade human cells, and the immune cells in the human body also recognize the virus through the spike protein. Researchers said that the new coronavirus has further adapted to the human body through mutation, but it does not necessarily mean that it has become more dangerous. Whether the latest mutant strain is “the wolf is coming” still needs to be looked at with a question mark.

Will the latest mutant strains exploit the protection of existing vaccines?

For ordinary people, the question of whether the latest mutant strains will exploit the protective power of existing vaccines is obviously more worthy of attention. Pfizer previously stated that a new vaccine against Omicron may take 100 days to be developed, and vaccine manufacturer Modena has also stated that it will “promptly advance a candidate vaccine for Omicron intensified injections.” Global news network news said that AstraZeneca said it is studying the impact of Omicron on its new crown vaccine and antibody combination drugs. AstraZeneca is collecting data and conducting research in two southern African countries, Botswana and Swatini. This will be a great breakthrough for the company in collecting real-world data on this mutant strain.

In the face of the powerful newest mutant strain Omicron, how much protection the vaccine can play is still unknown. Even for Delta, which is the most popular at the moment, the protective effect of the vaccine is not 100%. The mechanism of action of the new crown vaccine is the principle of immunity. The new coronavirus vaccine is a modified new coronavirus or part of the new coronavirus. When the human body is vaccinated by injection or other means, immunity will occur, and then protective antibodies and immune memory will be produced. At the same time, the quality of the vaccine itself is also very critical. The virus cannot escape 100%, and it will only reduce the level of comprehensive antibodies to a certain extent. For example, after an mRNA vaccine designed for wild-type is injected into the body, if the antibody level is 1000, when it encounters a mutant strain, its antibody level will be reduced to 400, and it may become even lower for the South African mutant strain Omicron. And if the second-generation vaccine is designed, using appropriate adjuvants, to improve the quality of the vaccine, and increase the level of antibodies, against this mutant strain, even if the vaccine’s efficacy is reduced to a certain extent, it still has sufficient clearance and protection against the virus. The protection rate of the human body.

From the perspective of past mutant strains, the new coronavirus is in the process of continuous mutation. The more transmissible viruses tend to have reduced pathogenicity, while the more infectious and pathogenic mutant strains are due to higher The fatality and morbidity symptoms are often difficult to develop into a pandemic. At present, research on all aspects of the new strain is still underway, and indicators of various dimensions need to be confirmed by research. The impact of the new strain Omicron needs to be treated rationally. At present, vaccination is still one of the most important prevention and control methods, and vaccines have performed well in protecting multiple mutant strains. Debon Securities analysts believe that the new crown epidemic is likely to continue, and its infectivity and toxicity are far greater than that of influenza viruses. It is difficult for a single method to play a decisive role in prevention and treatment. The combination of “prevention + treatment” will become the main prevention and control method for the new crown epidemic in the future; As a preventive vaccine, it is still the first choice for epidemic prevention and control. Only large-scale vaccination can build a solid first line of defense for epidemic prevention and control. Continuous upgrading of vaccines and regular vaccination may become the norm.

Experts’ latest judgment: Don’t panic too much

Jin Dongyan, a professor at the School of Biomedical Sciences of the University of Hong Kong and an expert in virology, said that more mutations in Omicron do not mean that Omicron is more infectious and pathogenic. Its infectivity and pathogenicity remain to be seen. At present, it is necessary to find out that it is in Africa. The epidemic situation. In his opinion, the protective efficacy of the vaccine may be reduced to Omicron, but it will not be completely ineffective, and oral medicine will not be affected. “Omicron is likely to appear in patients with immunodeficiency. We must strengthen vaccination for this part of the population to ensure that they produce enough antibodies to prevent them from becoming a hotbed of mutations of the new coronavirus.”

Zhong Nanshan, an academician of the Chinese Academy of Engineering, said: Judging from the current situation, the Omicron mutant strain is spreading fast and has been circulating in South Africa and other regions. Currently, there is not much knowledge about the mutant virus, but this virus carries a large number of mutations and is also useful for epidemic prevention. Presents more challenges. “This mutant strain is very new. Although molecular genetic testing has found that it has more changes in the receptor binding site, how harmful it is, how fast it will spread, whether it will make the disease more serious, and whether it is necessary To develop a vaccine against it, we still need to judge according to the situation. It is too early to draw a conclusion. The harmfulness of the Omicron mutant strain needs a period of time to be judged and needs to be paid attention to at any time, but no major action will be taken yet. One thing that needs more attention is to pay attention to the prevention and control of people entering South Africa in relevant areas.”

Michael Ryan, Executive Director of the WHO Health Emergencies Program, said: At present, the public does not need to worry too much about the new coronavirus variant. This is what scientists need to study. He said: “The people need to believe that we will give early warning in time.” “This situation will always happen, the virus will continue to evolve, and we will find them too,” but he still hopes that the people will not panic too much. “It is not the end of the world. , The sky hasn’t fallen yet.” (Bioon.com)