The 3rd dose is due! Omicron virus is as contagious as "measles". Vaccine booster shot can increase immune system "cross-reactivity"
Is Omicron virus less threatening? Scholar: The virus concentration in the lungs is low
The Omicron variant virus is spreading rapidly in various countries. Current studies in various countries have shown that Omicron is extremely contagious, but the severity of the disease is lower than that of the previously dominant dominant strain Delta. The research team of Michael Diamond, professor of virology at the University of Washington, recently found from animal experiments that the concentration in the lungs of mice infected with Omicron virus was only 1/10 compared to that of mice infected with other mutant viruses.
Is infection with Omicron virus really less of a health threat? The research team claimed that mice infected with Omicron virus did not lose significant weight, while in animals infected with other mutant viruses, weight loss was significantly positively correlated with severe complications.
Michael Diamond believes that the greatest damage caused by the original new coronavirus is in the lungs and the inflammatory immune response after infection. The virus destroys both infected and uninfected healthy cells. Lower virus concentrations in the lungs may indicate milder illness after infection.
Ravindra Gupta, professor of virology at the University of Cambridge, said that Omicron is as contagious as measles, but at present it seems that Omicron is more likely to replicate in upper respiratory tract infections. If the virus only stays in the upper respiratory tract, it is more likely to be expelled from the mouth and nose. This means that Omicron is more likely to cause local infection in the upper respiratory tract and is less likely to cause serious damage to the lungs.
However, these opinions are limited to current small studies, and larger-scale experimental data are still needed to determine the extent of Omicron’s impact on human health.
Are antibodies more protective against breakthrough infections after vaccination?
The authoritative journal “Nature” released news that a team from the National Institute of Infectious Diseases in Tokyo, Japan, conducted an immunity analysis on breakthrough infection cases who were infected with Alpha or Delta viruses after receiving two doses of the vaccine. It was believed that a longer period of time after vaccination When a breakthrough infection occurs (months later), antibodies produced by memory cells provide greater protection.
The team at the National Institute of Infectious Diseases in Tokyo believes that there may be more cases of breakthrough infections after previous vaccination, which provides the overall community with more protection against Omicron viruses, and this may be Omicron viruses. So far, there have been no causes of large-scale breakthrough infections in Japan.
Omicron spike protein mutant multi-vaccine booster effectively prevents infection
South Africa is the main country where the first wave of Omicron virus outbreaks occurred. A small study in the country found that Omicron’s spike protein has dozens of more mutations than Delta. Therefore, even after receiving two doses of vaccine, the immune system cannot produce energy. Antibodies that are completely resistant to Omicron, but there is still a certain degree of cross-immunity between the two. Serum experiments also found that the protection against Delta increased to a certain extent after infection with Omicron.
A pre-review research paper jointly released by the Ragon Institute of MIT and Harvard University points out that although the neutralizing antibodies obtained after 2 doses of the vaccine are not effective against Omicron infection, the booster dose can significantly improve the immunity through cross-reaction of immunity. By increasing the effective antibody value, even if the antibody type produced is not specific to Omicron virus, it can still effectively prevent infection.
Can’t we rely on natural immunity to fight Omicron? Will the new coronavirus become a regional epidemic?
However, natural immunity from Omicron infection may not induce protection against secondary infection. A South African study found that people who have been vaccinated against the new coronavirus will develop stronger antibody responses to the Omicron virus, while infected people who have never been vaccinated have varying immune responses to the virus. Especially in terms of hospitalization rates and severe complications, an immune system that is completely unvaccinated may have more risks facing Omicron.
Shiv Pillai, a professor at Harvard Medical School, believes that the increase in global vaccination coverage and the popularity of Omicron may cause the new coronavirus to shift from a global pandemic to a regional epidemic, and most people will be able to have certain long-term immunity to the new coronavirus. , the severe disease rate and mortality rate will be slower than before.
However, different types of COVID-19 will continue to exist in the ecosystem. If the interval between reinfections is too long or vaccine boosters are not administered, health may still be seriously affected, or a more dangerous and more dangerous virus may reappear. Immunity to escaped virus variants. Shiv Pillai said that humanity’s long-term fight against the new coronavirus may have to hope for the advent of clearly effective oral antiviral drugs.
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〈Omicron’s feeble attack on the lungs could make it less dangerous〉
〈Immunity against Omicron from breakthrough infection could be a matter of timing〉
