3 ms·

It's seems the author didn't review previous literature on heard imunity on covid. For instance, Manaus had 76% of serumprevalence in October and the number of

It's seems the author didn't review previous literature on heard imunity on covid. For instance, Manaus had 76% of serumprevalence in October and the number of new cases seem stable. Fast Forward to this week, the health system collapsed, highest number of deaths in one day. https://science.sciencemag.org/content/371/6526/288 https://science.sciencemag.org/content/371/6526/288 https://www.reuters.com/article/us-health-coronavirus-brazil-amazon/brazils-amazonas-state-running-out-of-oxygen-as-covid-19-surges-idUSKBN29J2SJ https://www.reuters.com/article/us-health-coronavirus-brazil... Most (all?) highly contagious viral infection only achieve heard imunity after widespread vaccination.

rossdavidh 6y ago
From the Science article you refer to: "When the percentage of infected people exceeds the herd immunity threshold of 60 to 67%, or 100 × [1 – (1/R0)], each infection generates fewer than one secondary case (case reproduction number Rt < 1) and incidence declines."
- boibombeiro 6y ago
  They used a similar reasoning as OP. The huge increase on hospitalization in this month suggests heard imunity might not be possible. Either due reinfection, either because a more agressive variant is infecting people not yet imune. Reports from region says the number of people with 40-50 years hospitalized substianlly increased when compared with first wave. This new wave of infections seems to be caused by a new variant called P1, it include both B117 (UK) and E484K (SA) mutations. This hypotesys is still under investigation, given the lack of genomic sequentialing during the first wave. Yesterday a paper on this new variant was published (and given a new name). People should be aware that is unlikely heard imunity will be achieved without vaccination. RNA virus are known to have a high mutations rate, and despite covid having a low mutation rate (given its large rna size), it still mutates a lot. And natural selection will favors the variation that spreads more.

rossdavidh 6y ago

From the Science article you refer to: "When the percentage of infected people exceeds the herd immunity threshold of 60 to 67%, or 100 × [1 – (1/R0)], each infection generates fewer than one secondary case (case reproduction number Rt < 1) and incidence declines."

boibombeiro 6y ago
They used a similar reasoning as OP. The huge increase on hospitalization in this month suggests heard imunity might not be possible. Either due reinfection, either because a more agressive variant is infecting people not yet imune. Reports from region says the number of people with 40-50 years hospitalized substianlly increased when compared with first wave. This new wave of infections seems to be caused by a new variant called P1, it include both B117 (UK) and E484K (SA) mutations. This hypotesys is still under investigation, given the lack of genomic sequentialing during the first wave. Yesterday a paper on this new variant was published (and given a new name). People should be aware that is unlikely heard imunity will be achieved without vaccination. RNA virus are known to have a high mutations rate, and despite covid having a low mutation rate (given its large rna size), it still mutates a lot. And natural selection will favors the variation that spreads more.