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When will the Covid-19 epidemic end?
Celine Deluzarche
Journalist
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Modified on 23/09/2021
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Don't expect a drop in virulence
One of the widespread beliefs is that the virus loses its virulence as the pandemic progresses so as not to kill its host, which is also its transmission vector. Unfortunately, this view does not stand up to the analysis of the facts, for example HIV has become more virulent over time. Likewise, the Delta variant appears to cause more severe forms than the Alpha variant. " In the case of SARS-CoV-2, severe symptoms usually appear after two weeks of infection, but more than 95% of transmissions occur before day 11. In other words, from the perspective of this coronavirus, late (particularly inflammatory) manifestations of virulence do not constitute a loss of transmission opportunities.”, says Samuel Alizon, Director of Research at the CNRS and the IRD.
Only one disease in history has been eradicated with a vaccine : smallpox , the last known case of which dates back to 1978 in the United Kingdom. “ This eradication has been possible at the cost of relentless vaccination campaigns for decades. In addition, SARS-CoV-2 has an animal reservoir, so it is almost impossible to eradicate the virus, such as the pathogen of plague, for example, ”says Eric Dortenzio, research director at Inserm. In fact, most of the viruses or bacteria responsible for past pandemics are still present today, be it plague, H1N1 or Ebola. Diseases that are still experiencing sporadic epidemic upsurges.“
Even if the virus were eradicated from the human population, it would continue to circulate in animals and could undergo unexpected mutations.
According to experts, the safest way to end an epidemic is to slow the spread of the disease and counteract its side effects.
Pest control and hygiene standards, for example, have helped control plague and cholera . Triple therapies have drastically reduced AIDS mortality . In the case of measles , vaccination makes it possible to reduce the number of contaminations to almost zero, but this requires practically 100% vaccination coverage and the immunity conferred by the vaccine to be sterilizing. that is, it prevents the transmission of the virus. Two conditions that will undoubtedly never be met with Covid-19. " Even if we eradicated the virus in the human population, it would continue to circulate in animals and could undergo unexpected mutations there , ”warns Jean-Claude Manuguerra.
...
When will the Covid-19 epidemic end?
Celine Deluzarche
Journalist
...
Modified on 23/09/2021
...
Don't expect a drop in virulence
One of the widespread beliefs is that the virus loses its virulence as the pandemic progresses so as not to kill its host, which is also its transmission vector. Unfortunately, this view does not stand up to the analysis of the facts, for example HIV has become more virulent over time. Likewise, the Delta variant appears to cause more severe forms than the Alpha variant. " In the case of SARS-CoV-2, severe symptoms usually appear after two weeks of infection, but more than 95% of transmissions occur before day 11. In other words, from the perspective of this coronavirus, late (particularly inflammatory) manifestations of virulence do not constitute a loss of transmission opportunities.”, says Samuel Alizon, Director of Research at the CNRS and the IRD.
Only one disease in history has been eradicated with a vaccine : smallpox , the last known case of which dates back to 1978 in the United Kingdom. “ This eradication has been possible at the cost of relentless vaccination campaigns for decades. In addition, SARS-CoV-2 has an animal reservoir, so it is almost impossible to eradicate the virus, such as the pathogen of plague, for example, ”says Eric Dortenzio, research director at Inserm. In fact, most of the viruses or bacteria responsible for past pandemics are still present today, be it plague, H1N1 or Ebola. Diseases that are still experiencing sporadic epidemic upsurges.“
Even if the virus were eradicated from the human population, it would continue to circulate in animals and could undergo unexpected mutations.
According to experts, the safest way to end an epidemic is to slow the spread of the disease and counteract its side effects.
Pest control and hygiene standards, for example, have helped control plague and cholera . Triple therapies have drastically reduced AIDS mortality . In the case of measles , vaccination makes it possible to reduce the number of contaminations to almost zero, but this requires practically 100% vaccination coverage and the immunity conferred by the vaccine to be sterilizing. that is, it prevents the transmission of the virus. Two conditions that will undoubtedly never be met with Covid-19. " Even if we eradicated the virus in the human population, it would continue to circulate in animals and could undergo unexpected mutations there , ”warns Jean-Claude Manuguerra.
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