Novel coronavirus usually infects humans through the respiratory tract and causes damage to the respiratory system and various organs of the human body. Since the first outbreak at the end of 2019, the novel coronavirus is still raging around the world, causing a great negative impact on the world economy and society.
Novel coronavirus usually infects humans through the respiratory tract and causes damage to the respiratory system and various organs of the human body. Since the first outbreak at the end of 2019, the novel coronavirus is still raging around the world, causing a great negative impact on the world economy and society.
With the large-scale prevalence of novel coronavirus, new virus mutants continue to appear. At present, Omicron mutant is the most concerned strain in the world.
For a long time, a common assumption for novel coronavirus is that natural immune enhancement can be obtained by infecting the virus, which can better identify the virus and resist future infection. But what about the facts?
On June 14, 2022, researchers from Imperial College London published a research paper entitled "immune boosting by b.1.1.529 (Omicron) depends on previous sars-cov-2 exposure" on the top international medical journal "science".
This study shows that infection with Omicron can not effectively enhance immunity. Even among the people who have been vaccinated with three doses of vaccine, infection with Omicron has poor natural enhancement effect on Omicron reinfection.
Specifically, Omicron infection provided immune enhancement against previous variants, including alpha, beta, gamma, Delta, and the original strain, in people who had received three doses of vaccine and had not previously been infected with the new crown. However, the immune enhancement effect on Omicron itself is small. Those who were infected during the first pandemic and then by Omicron did not receive any reinforcement.
This study explains why breakthrough infection and repeated infection have been the characteristics of the pandemic during the Omicron epidemic.
The researchers said that Omicron is not a benign natural vaccine immune enhancer, but a special hidden immune evasion agent.
In this study, the researchers analyzed the blood samples of British medical staff who received three doses of mRNA vaccine and had different history of new coronal infection to study the antibody, T cell and B cell immunity against Omicron.
The study found that among the people who had been vaccinated with three doses of vaccine, those who had not previously been infected with sars-cov-2 showed enhanced cross reactive immunity to the previous variants after infection with Omicron, which enhanced the immunity of B cells and T cells to alpha, beta, gamma and delta, but weakened the enhancement of Omicron spinous protein itself.
Significant reduction of cross reactive antibodies against Omicron
The antibody response to Omicron in people previously infected with alpha was not very persistent. After infection during the first pandemic, people who re infected with Omicron did not have any immune enhancement effect. The researchers called this effect "mixed immunosuppression".
According to the researchers, people previously infected during the first wave of infection will not be infected with Omicron and the sub variant ba 4 and ba 5 carry out immune enhancement.
The researchers stressed that although the study highlighted clear concerns about the nature of Omicron infection, vaccination can prevent serious diseases and deaths, and people should be encouraged to strengthen immunization. However, the long-term health impact of the vaccine on the sequelae of the new crown is not clear.
In conclusion, this study extinguished the idea of regarding Omicron infection as a "natural vaccine". Omicron is not a benign natural vaccine immune enhancer.
Paper link:
DOI:10.1126/science. abq1841
Original link:
https://www.cn-healthcare.com/articlewm/20220615/content-1381551.html
