Omicron has a small amount of virus but is super powerful? Is Herd Immunity No Hope? Scholars exclaimed: Everyone will fall into the trap
Does high viral load mean strong contagion? Omicron experiment falls below expert glasses
Why can Omicron spread in large numbers at lightning speed and quickly become various major popular mutant strains? Emily Bruce, a virologist at the University of Vermont in the United States, pointed out in the latest preprint study that Omicron can escape immunity generated by vaccination or infection with other virus strains. Although the amount of virus in infected people is not as high as Delta, Omicron is only 2 Within months, it became the dominant strain of new cases in the United States.
In order to compare the “viral loads” of different strains, Yonatan Grad’s team, a professor of infectious diseases at Harvard School of Public Health, collected physical examination data from NBA players and related staff and found that the highest viral load in people infected with Delta virus was much higher. At Omicron, he overturned the existing idea that a higher viral load equals a stronger infectivity.
Benjamin Meyer’s team, a virologist at the University of Geneva, previously used blood samples from people with “breakthrough infections” who had been vaccinated but were still infected with Delta and found that 5 days after a positive screening test, half still contained infectious viruses.
The Grad team’s screening results for Omicron-positive individuals also showed the same result. Grad said that the amount of virus after infection with Omicron is highly variable, and being quarantined for 5 days does not mean that there is no infectivity, which will make it more difficult to adjust the public health quarantine policy.
Is there any hope of herd immunity? Scholar: Everyone will get the new coronavirus
It has been two years since the COVID-19 pandemic began. Although various countries have implemented large-scale vaccinations, herd immunity has not yet been achieved. Does the pandemic of the Omicron variant mean that “herd immunity” will be unattainable? According to the latest report from “Reuters”, many public health experts claimed in the early days of the pandemic that as long as a sufficient proportion of the population was vaccinated or infected, it would be possible to achieve herd immunity against the new coronavirus, but this hope seems to have “become considerable.” Slim."
World Health Organization (WHO) epidemiologist Olivier le Polain told Reuters that judging from the current epidemic situation of the new coronavirus, it may be unrealistic to completely eliminate the virus infection. There is growing evidence that vaccination or previous infection can help improve a population’s immunity to Covid-19, but this is not entirely consistent with the so-called “herd immunity” goal.
Marc Lipsitch, an epidemiologist at the Harvard School of Public Health, mentioned in an interview with Reuters that there are two reasons why herd immunity may not be achieved. The first is the rapid decay of immunity. Whether it is vaccination or infection with the virus, the immunity provided by The protection time is not long. The second is the rapid mutation of the virus, allowing mutant strains to escape the protective effect caused by vaccination or previous infection.
David Wohl, an infectious disease expert at the University of North Carolina, believes that if vaccinated people still have the ability to spread the virus and infect others, “the rules of the game have changed!” It is possible that most people will be infected with Omicron strain, but the protection gained from infection with Omicron may not be effective against the next mutant strain.
Francois Balloux, professor of “Computational Systems Biology” at the University of London, said that the media initially told people that humans would achieve herd immunity when 60% of the population was vaccinated, but this did not happen. Later, there was another claim that 80% of the population would be vaccinated and herd immunity could be achieved. The reality is that this hope was once again disappointed.
Balloux told Reuters in an interview that although it sounds worrying, the vast majority of people will be exposed to and infected with the new coronavirus, and people should prepare early.
Will COVID-19 come back but the pandemic won’t?
However, some scholars have a positive view on the future of the epidemic. Christopher JL Murray, a professor at the University of Washington, published a paper in “The Lancet” and concluded that between November 2021 and the end of March 2022, 50% of the world’s population will be infected with the Omicron virus.
Murray pointed out that South African data even showed that 90% of the infected population were asymptomatic. In Canada and South Africa, the proportion of intubations and deaths due to the new coronavirus has dropped by 80-90%, and the severity of the disease has decreased. However, a large number of medical workers diagnosed positive will be a greater test.
Murray emphasized that the IHME model shows that Omicron has a strong transmission ability. Even if mask restrictions are increased, vaccinations are expanded, and the third booster dose is provided, I am afraid that in countries that have caused large-scale infections, the impact of limiting infection will be limited. Murray predicts that the global population’s immunity to the new coronavirus will reach its peak after March, and the spread of the virus will decrease significantly in the next few months.
Murray believes that the impact of the new coronavirus on human health will gradually become smaller in the future. This is because humans have been widely exposed to the virus, coupled with vaccine updates, the emergence of antiviral drugs, and people wearing masks and maintaining social distance will help reduce the risk. Correct concept of contagion. COVID-19 may be a “recurring” infectious disease in the future, causing waves of epidemics in specific seasons, but the scale and impact will be significantly lower.
“COVID-19 may come back, but the pandemic won’t,” Murray believes.
source:
How does Omicron spread so fast? A high viral load isn’t the answer
Viral dynamics and duration of PCR positivity of the SARS-CoV-2 Omicron variant
Analysis: How Omicron highlights fading hope of herd immunity from COVID
COVID-19 will continue but the end of the pandemic is near
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