6 ms·

The disease also appears to spread much faster than the flu. So even if the death rate is comparable, the infection rate is likely to be far higher.

by pcl 7y ago

eteos 7y ago
This is likely because our immume system is not familliar with this virus yet.
- Jedd 7y ago
  This doesn't add up either -- immunity per individual is expected to last 'only a few months', opening the door to multiple infections per year per person.
  - easytiger 7y ago
    > This doesn't add up either -- immunity per individual is expected to last 'only a few months', There is no evidence either way. Even if it is transient it will be enough for it to die down
    - Jedd 7y ago
      There's some very strong indicators that immunity will be ephemeral. It's possible the R naught will drop below the currently assessed 2.2 over time, but there's no evidence for that -- and if both these things stay as expected, it won't be transient enough to 'die down' naturally.
      - easytiger 7y ago
        Unfortunately until we get an antigen test, we will not know for sure. But there is no reason to believe at this point that it isn't anything other than a standard immune response. It would extremely rare that it wasn't
  - bart_spoon 7y ago
    There's no indication how long the immunity is expected to last. It's just as likely that immunity, even if temporary, can last for a year or more, as is the case with the flu or some other viruses.
    - Jedd 7y ago
      On HN this morning -- news that someone in Japan is already on their second infection of this virus. So there's our first data point.
bryanrasmussen 7y ago
let's say there were 320,000 people without symptoms in China, which seems unlikely, that would make the total cases approximately 400000, and if we just looked at the fatalities so far out of that it would be a fatality rate of 0.8% iirc the common flu is 0.1% fatality, so if this only had 0.8% but affects 40-70% of the world (which seems to me like it would be at the 70% end if there are lots of asymptomatic people) so 40% of 7 billion and then 0.8% of that is 22,400,000 - my math is probably off here.
- dnautics 7y ago
  > 320,000 people without symptoms in China Wuhan (the city, not even the entire province of Hubei) has 11 million people. Given what we know now about how virulently and covertly COVID-19 spreads and how (relatively late) Wuhan went into lockdown, how do you feel about that number?
  - bryanrasmussen 7y ago
    if 50% to 75% of cases are asymptomatic that means 25% to 50% are symptomatic. I'm not taking the exact 75% number here in the following - but close, and I will do some hasty approximations. Current total cases (maybe off by some hours) is 80,894. 80894 is 20.2% of 400000. 400000 - 80000 = 320000. So yes, given the article's premises 320000 is pretty much on the optimistic side for humanity. on edit: but once again my math is probably off somewhere so correct it if you see some glaring error in my reasoning. Also note these numbers are for China, of course.
    - dnautics 7y ago
      you're assuming everyone is capable of being infected to detectable levels.
      - bryanrasmussen 7y ago
        no that is exactly what I am not doing, hence my starting off my explanation with: "if 50% to 75% of cases are asymptomatic that means 25% to 50% are symptomatic." then I go ahead and choose a number (400000) which is on the optimistic end of this range - 80894 is 20.2% of 400000 - I believe that is quite clear, if 80894 is 20.2% of 400000 and 80894 is the amount of total cases counted in China (no longer the case) then I am assuming 79.8% people asymptomatic that have not been counted! (although of course I did some simplifying of things around so my percentages and numbers are not exact, but I think given the linked article slightly under 320000 people being asymptomatic and 80894 being symptomatic is a very optimistic take) what number do you want to assume is not counted? millions? I assume that from your earlier post but that does not follow from the 50% to 75% cases are asymptomatic. Obviously if 50% to 75% are asymptomatic and you had 1 million people infected all together (symptomatic and asymptomatic) that would mean you needed to have at least 250000 (25% of a million) to 500000 (50% of a million) people symptomatic. But we don't have those numbers symptomatic, we have slightly under 81000.

The disease also appears to spread much faster than the flu. So even if the death rate is comparable, the infection rate is likely to be far higher.

by pcl 7y ago

The disease also appears to spread much faster than the flu. So even if the death rate is comparable, the infection rate is likely to be far higher.

eteos 7y ago

This is likely because our immume system is not familliar with this virus yet.

Jedd 7y ago
This doesn't add up either -- immunity per individual is expected to last 'only a few months', opening the door to multiple infections per year per person.
- easytiger 7y ago
  > This doesn't add up either -- immunity per individual is expected to last 'only a few months', There is no evidence either way. Even if it is transient it will be enough for it to die down
  - Jedd 7y ago
    There's some very strong indicators that immunity will be ephemeral. It's possible the R naught will drop below the currently assessed 2.2 over time, but there's no evidence for that -- and if both these things stay as expected, it won't be transient enough to 'die down' naturally.
    - easytiger 7y ago
      Unfortunately until we get an antigen test, we will not know for sure. But there is no reason to believe at this point that it isn't anything other than a standard immune response. It would extremely rare that it wasn't
- bart_spoon 7y ago
  There's no indication how long the immunity is expected to last. It's just as likely that immunity, even if temporary, can last for a year or more, as is the case with the flu or some other viruses.
  - Jedd 7y ago
    On HN this morning -- news that someone in Japan is already on their second infection of this virus. So there's our first data point.

bryanrasmussen 7y ago

let's say there were 320,000 people without symptoms in China, which seems unlikely, that would make the total cases approximately 400000, and if we just looked at the fatalities so far out of that it would be a fatality rate of 0.8% iirc the common flu is 0.1% fatality, so if this only had 0.8% but affects 40-70% of the world (which seems to me like it would be at the 70% end if there are lots of asymptomatic people) so 40% of 7 billion and then 0.8% of that is 22,400,000 - my math is probably off here.

dnautics 7y ago
> 320,000 people without symptoms in China Wuhan (the city, not even the entire province of Hubei) has 11 million people. Given what we know now about how virulently and covertly COVID-19 spreads and how (relatively late) Wuhan went into lockdown, how do you feel about that number?
- bryanrasmussen 7y ago
  if 50% to 75% of cases are asymptomatic that means 25% to 50% are symptomatic. I'm not taking the exact 75% number here in the following - but close, and I will do some hasty approximations. Current total cases (maybe off by some hours) is 80,894. 80894 is 20.2% of 400000. 400000 - 80000 = 320000. So yes, given the article's premises 320000 is pretty much on the optimistic side for humanity. on edit: but once again my math is probably off somewhere so correct it if you see some glaring error in my reasoning. Also note these numbers are for China, of course.
  - dnautics 7y ago
    you're assuming everyone is capable of being infected to detectable levels.
    - bryanrasmussen 7y ago
      no that is exactly what I am not doing, hence my starting off my explanation with: "if 50% to 75% of cases are asymptomatic that means 25% to 50% are symptomatic." then I go ahead and choose a number (400000) which is on the optimistic end of this range - 80894 is 20.2% of 400000 - I believe that is quite clear, if 80894 is 20.2% of 400000 and 80894 is the amount of total cases counted in China (no longer the case) then I am assuming 79.8% people asymptomatic that have not been counted! (although of course I did some simplifying of things around so my percentages and numbers are not exact, but I think given the linked article slightly under 320000 people being asymptomatic and 80894 being symptomatic is a very optimistic take) what number do you want to assume is not counted? millions? I assume that from your earlier post but that does not follow from the 50% to 75% cases are asymptomatic. Obviously if 50% to 75% are asymptomatic and you had 1 million people infected all together (symptomatic and asymptomatic) that would mean you needed to have at least 250000 (25% of a million) to 500000 (50% of a million) people symptomatic. But we don't have those numbers symptomatic, we have slightly under 81000.