4 ms·

It's a good question. I've been thinking of it this way; If we have an "unlimited" (by which I mean we manufacture them faster than we consume them) number of

It's a good question. I've been thinking of it this way; If we have an "unlimited" (by which I mean we manufacture them faster than we consume them) number of test kits with a turnaround time of < 24 hrs, then everyone on lock down for 14 days. Medical/Drive through facilities set up to process everyone for a test. Get a test, and then within 24 hours get a text on what their status is (infected, uninfected, immune (post infection)). People who test positive go into quarantine to be re-tested weekly until they are immune. People who test immune are allowed to resume work movement while keeping good practice (washing hands, coughing into elbow, Etc.) People who test as non-infected are required to come back for re-testing every week, can move around with social distancing. I don't know if it would work (I'm not a public health professional) but from a systems perspective surveillance of the infection seems to be the best strategy for staying on top of outbreaks. Once a vaccine is available it becomes one of the things you get every year like a flu shot.

pmoriarty 7y ago
Regarding immunity, there is evidence that such immunity (if it exists) is short-lived, and after a little while recovered individuals are susceptible to being infected again.
- tonyedgecombe 7y ago
  Do you have a reference for that as I keep hearing it repeated but I'm yet to see any real evidence for it.
  - hluska 7y ago
    I’m not OP, just a concerned parent who is trying to figure things out. I have not been able to locate a single scientific study about this. Rather, the evidence all seems to be news reports of people testing positive, then negative and then positive again. Since it isn’t scientific, all the usual caveats apply - we don’t know much about how effective those tests were and again, these are news reports. If you’re interested, I can post some news reports. Forbes actually has a pretty good rundown of the various news articles, but Forbes isn’t always the best place for facts or safe browsing, so I’ll avoid posting that one. In the interest of fairness, I can also post (much older) news reports that called HIV/AIDS “Gay Related Immuno-deficiency” and we know how good that science was.
    - timhigins 7y ago
      The truth is that these current tests (rt RT-PCR) are not completely accurate and may only have a true positive rate of 60-70%. See Discussion section of: https://pubs.rsna.org/doi/10.1148/radiol.2020200642 https://pubs.rsna.org/doi/10.1148/radiol.2020200642 Additionally, people who are asymptomatic can test negative on all of their tests and only be diagnosed via other means. See Figure 1 here: https://link.springer.com/content/pdf/10.1007/s11427-020-1661-4.pdf https://link.springer.com/content/pdf/10.1007/s11427-020-166...
      - projektfu 7y ago
        You have that a little backwards. The positive predictive value in the discussion is for CT. rtPCR is being used as the definitive test but it lacks sensitivity so it has false negatives. The 59% rate for rtPCR positive suggests that they are missing cases that CT might catch. However, the CT findings are not “pathognomonic” meaning that other conditions can cause the appearance of viral pneumonia (such as influenza).
  - pmoriarty 7y ago
    Here's what Ralph Baric, an epidemiologist from the University of North Carolina Chapel Hill, had this to say on episode 591 of This Week in Virology[1] a couple of days ago: Ralph Baric: "I saw some very interesting data from Stan Perlman the other day, who has been looking at serum neutralization titers of MERS patients from the Middle East kingdom of Saudi Arabia area and it's quite intersting that people peak fairly quickly with high neutralization titers but then they wane over the next year to almost background levels or just slightly above background levels by the second year, and with MERS there have been several reports of people who have seroconverted. They were rtPCR positive and their serum neutralizing titers and even ELISA titers went to almost zero within a few months." Baric: "And it has not been studied and it should be studied, and this is the contemporary human Coronaviruses -- nobody knows how they maintain themselves in human populations. They don't undergo rapid antigenic variation like influenza. There's not 115 common cold or corona virus type genotypes or whatever they're called, serotypes. Sorry Vincent, I just butchered the coronaviruses." Vincent Racaniello: "That's ok." <laughter> Baric: "So one hypothesis is that they cause a transient protective immune response that wanes quickly and then they can reinfect and cause mild upper-respiratory tract infections and that's how they maintain themselves. So it is quite possible.. there's been a number now of reported cases in China of SARS2 infections where people were documented to be infected and recovered. They were rtPCR negative. They went home and they became reinfected a month later or so." Baric: "In this case the United States has sufficient cases that we can actually track the serologic responses of the individuals and their general immune.. both B- and T-cell responses after infection and we can get a handle on the long term immunity that may be elicited after infection." [1] - http://www.microbe.tv/twiv/twiv-591/ http://www.microbe.tv/twiv/twiv-591/ [2] - about 15 minutes and 50 seconds in to the program
    - gomox 7y ago
      Could you clarify this for laymen?
      - Johnjonjoan 7y ago
        There's precedent, it makes sense with our knowledge, we have seen people who are apparently reinfected, we can likely soon find evidence for or against the idea

pmoriarty 7y ago

Regarding immunity, there is evidence that such immunity (if it exists) is short-lived, and after a little while recovered individuals are susceptible to being infected again.

tonyedgecombe 7y ago
Do you have a reference for that as I keep hearing it repeated but I'm yet to see any real evidence for it.
- hluska 7y ago
  I’m not OP, just a concerned parent who is trying to figure things out. I have not been able to locate a single scientific study about this. Rather, the evidence all seems to be news reports of people testing positive, then negative and then positive again. Since it isn’t scientific, all the usual caveats apply - we don’t know much about how effective those tests were and again, these are news reports. If you’re interested, I can post some news reports. Forbes actually has a pretty good rundown of the various news articles, but Forbes isn’t always the best place for facts or safe browsing, so I’ll avoid posting that one. In the interest of fairness, I can also post (much older) news reports that called HIV/AIDS “Gay Related Immuno-deficiency” and we know how good that science was.
  - timhigins 7y ago
    The truth is that these current tests (rt RT-PCR) are not completely accurate and may only have a true positive rate of 60-70%. See Discussion section of: https://pubs.rsna.org/doi/10.1148/radiol.2020200642 https://pubs.rsna.org/doi/10.1148/radiol.2020200642 Additionally, people who are asymptomatic can test negative on all of their tests and only be diagnosed via other means. See Figure 1 here: https://link.springer.com/content/pdf/10.1007/s11427-020-1661-4.pdf https://link.springer.com/content/pdf/10.1007/s11427-020-166...
    - projektfu 7y ago
      You have that a little backwards. The positive predictive value in the discussion is for CT. rtPCR is being used as the definitive test but it lacks sensitivity so it has false negatives. The 59% rate for rtPCR positive suggests that they are missing cases that CT might catch. However, the CT findings are not “pathognomonic” meaning that other conditions can cause the appearance of viral pneumonia (such as influenza).
- pmoriarty 7y ago
  Here's what Ralph Baric, an epidemiologist from the University of North Carolina Chapel Hill, had this to say on episode 591 of This Week in Virology[1] a couple of days ago: Ralph Baric: "I saw some very interesting data from Stan Perlman the other day, who has been looking at serum neutralization titers of MERS patients from the Middle East kingdom of Saudi Arabia area and it's quite intersting that people peak fairly quickly with high neutralization titers but then they wane over the next year to almost background levels or just slightly above background levels by the second year, and with MERS there have been several reports of people who have seroconverted. They were rtPCR positive and their serum neutralizing titers and even ELISA titers went to almost zero within a few months." Baric: "And it has not been studied and it should be studied, and this is the contemporary human Coronaviruses -- nobody knows how they maintain themselves in human populations. They don't undergo rapid antigenic variation like influenza. There's not 115 common cold or corona virus type genotypes or whatever they're called, serotypes. Sorry Vincent, I just butchered the coronaviruses." Vincent Racaniello: "That's ok." <laughter> Baric: "So one hypothesis is that they cause a transient protective immune response that wanes quickly and then they can reinfect and cause mild upper-respiratory tract infections and that's how they maintain themselves. So it is quite possible.. there's been a number now of reported cases in China of SARS2 infections where people were documented to be infected and recovered. They were rtPCR negative. They went home and they became reinfected a month later or so." Baric: "In this case the United States has sufficient cases that we can actually track the serologic responses of the individuals and their general immune.. both B- and T-cell responses after infection and we can get a handle on the long term immunity that may be elicited after infection." [1] - http://www.microbe.tv/twiv/twiv-591/ http://www.microbe.tv/twiv/twiv-591/ [2] - about 15 minutes and 50 seconds in to the program
  - gomox 7y ago
    Could you clarify this for laymen?
    - Johnjonjoan 7y ago
      There's precedent, it makes sense with our knowledge, we have seen people who are apparently reinfected, we can likely soon find evidence for or against the idea