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Reinfection

  • 24-08-2020 1:07pm
    #1
    Registered Users Posts: 5,045 ✭✭✭ blindjustice


    https://news.rthk.hk/rthk/en/component/k2/1545589-20200824.htm?spTabChangeable=0

    Researchers at the University of Hong Kong on Monday said they have proved that a Hong Kong man was infected with Covid-19 for a second time – the world’s first such documented case.

    The 33-year-old IT worker was cleared of Covid-19 and discharged from a hospital in April. He tested positive for the virus again after returning from Spain earlier this month.

    Health officials at first were unsure if the man was a "persistent carrier" of the virus from his previous infection.

    But the HKU research team said genetic sequencing showed the virus strains contracted by him in April and August were “clearly different”. The study has been accepted by the Clinical Infectious Diseases journal, the researchers said.

    “Many believe that recovered Covid-19 patients have immunity against re-infection because most developed a serum neutralising antibody response. However, there is evidence that some patients have waning antibody level after a few months," the researchers said.

    “Our findings suggest that the SARS-CoV-2 may persist in the global human population as is the case for other common cold-associated human coronaviruses, even if patients have acquired immunity via natural infection,” they said.


Comments

  • Registered Users Posts: 1,498 ✭✭✭ SeaBreezes


    https://news.rthk.hk/rthk/en/component/k2/1545589-20200824.htm?spTabChangeable=0

    Researchers at the University of Hong Kong on Monday said they have proved that a Hong Kong man was infected with Covid-19 for a second time – the world’s first such documented case.

    The 33-year-old IT worker was cleared of Covid-19 and discharged from a hospital in April. He tested positive for the virus again after returning from Spain earlier this month.

    Health officials at first were unsure if the man was a "persistent carrier" of the virus from his previous infection.

    But the HKU research team said genetic sequencing showed the virus strains contracted by him in April and August were “clearly different”. The study has been accepted by the Clinical Infectious Diseases journal, the researchers said.

    “Many believe that recovered Covid-19 patients have immunity against re-infection because most developed a serum neutralising antibody response. However, there is evidence that some patients have waning antibody level after a few months," the researchers said.

    “Our findings suggest that the SARS-CoV-2 may persist in the global human population as is the case for other common cold-associated human coronaviruses, even if patients have acquired immunity via natural infection,” they said.

    Its not the first case, does anyone know if 2nd time infection was mild or severe?

    Curious if he had some form of immunity after first strain dose (and only mild symptoms) or if effects are cumulative and more severe each strain.


  • Registered Users Posts: 960 ✭✭✭ darjeeling


    A reporter at the SCMP has posted up half the paper - results & discussion, no figures:

    https://twitter.com/cwylilian/status/1297857565385093121

    Details of the case:

    33yo healthy male experienced fever, headache, cough, sore throat from March 26-29, admitted to hospital on 29th after symptoms had subsided.

    Returned to Hong Kong from Spain via the UK on Aug 15th and tested positive during border screening.
    On reinfection, lowest qPCR Ct (i.e. highest viral load) detected was 26.7, on admission to hospital.
    Patient had no symptoms other than initial slightly elevated C-reactive protein (a blood marker of inflammation). Also low potassium, though I don't know if this is a symptom. Temperature was normal.

    A serum sample taken 10 days after the March infection was negative for IgG against the SARS-CoV-2 nucleoprotein.
    Serum was negative for IgG one day after readmission in August, turning positive on day five.


  • Moderators, Social & Fun Moderators, Society & Culture Moderators, Regional North Mods, Regional West Moderators Posts: 81,470 Mod ✭✭✭✭ biko




  • Registered Users Posts: 5,468 ✭✭✭ Badly Drunk Boy


    There are two more cases, in The Netherlands and Belgium.

    https://www.rte.ie/news/world/2020/0825/1161101-coronavirus-world/

    The Dutch patient was an older person with a weakened immune system, and the Belgian has mild symptoms.


  • Registered Users Posts: 3,124 ✭✭✭ tobefrank321


    Can false positives on the original tests be ruled out?

    Strange how the Hong Kong case tested positive but then negative for antibodies 10 days later, although possibly it was too soon for an antibody test.


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  • Registered Users Posts: 510 ✭✭✭ Mike3549


    But is it covid19? It clearly says different strain of corona. Is it as contagious as covid19? To me it looks more like media scaremongering


  • Registered Users Posts: 13,490 ✭✭✭✭ partyjungle


    Mike3549 wrote: »
    But is it covid19? It clearly says different strain of corona. Is it as contagious as covid19? To me it looks more like media scaremongering

    So sick of hearing this


  • Registered Users Posts: 960 ✭✭✭ darjeeling


    Can false positives on the original tests be ruled out?

    Strange how the Hong Kong case tested positive but then negative for antibodies 10 days later, although possibly it was too soon for an antibody test.
    Can false positives on the original tests be ruled out?

    Strange how the Hong Kong case tested positive but then negative for antibodies 10 days later, although possibly it was too soon for an antibody test.

    Yes, I think false positives can be excluded.

    The man had typical symptoms and a positive PCR test. He was released from hospital 14 days after admission, after two negative PCR tests 24 hours apart. The paper doesn't state, but I infer, that he must have tested positive during those 14 days or he would have been discharged earlier.
    Further, researchers were able to isolate and sequence the entire viral genome from a sample given during the initial infection.
    Mike3549 wrote: »
    But is it covid19? It clearly says different strain of corona. Is it as contagious as covid19? To me it looks more like media scaremongering

    The word 'strain' is used loosely, especially by journalists. Different strains really should have different biology - e.g. you could be infected with one strain, recover, and then not have immunity to infection by a second strain even very soon after.

    SARS-CoV-2 viral genome sequences from thousands of patients worldwide and spanning the whole pandemic have been generated and analysed. From this we see mutations accumulating over time, generating increasing diversity. Still, all of the genomes are very similar and can all be traced back to a recent common ancestor that matches early sequences from Wuhan.

    The two genome sequences from the patient in the paper differed by just 24 positions out of the 30,000 in the genome - i.e. they were more than 99.9% identical. The closest other known virus is a bat virus with only 97% identity to SARS-CoV-2.

    So The patient had very slightly different versions of the same virus, and it's probably premature to call them different strains.


  • Registered Users Posts: 5,942 ✭✭✭ topper75


    I gather from French media (my French is poor so need help/confirmation) that the second infection is much lighter.
    Anyone have anything on that yet?


  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh


    Resurrecting this thread for discussing the issue of reinfection.

    Are these cases the early signs of natural immunity failing?

    https://twitter.com/Forbes/status/1316111389057048579?s=19

    https://twitter.com/TIME/status/1316091775132598275?s=19


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  • Registered Users Posts: 9,795 ✭✭✭ raind


    igCorcaigh wrote: »
    Resurrecting this thread for discussing the issue of reinfection.

    Are these cases the early signs of natural immunity failing?

    https://twitter.com/Forbes/status/1316111389057048579?s=19

    https://twitter.com/TIME/status/1316091775132598275?s=19

    Comments on both cases:

    First was a severely immunity compromised individual

    Second included this comment from a Harvard professor of epidemiology
    “Re-exposures are essential to build our immune system,” Mina wrote. “But like anything, when enough people get a re-exposure, there are going to be rare cases here and there that go awry and someone gets more sick the second time.”


  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh


    As for vaccines:

    “While [the study] may speak to our own natural immunity, vaccine-based immunity is often very different than that,” Pandori says.


  • Registered Users Posts: 695 ✭✭✭ DaSilva


    Immunity is probably really nuanced, The case of the dutch woman re-infected with sars-cov-2 who died was 80 years old and undergoing cancer treatment (often this leads to lower immunity but I'm not sure on the details of this case)

    We are used to thinking in binary terms, immune and not immune, and vaccination / infection leads to total immunity, but I have read that people get regularly re-infected with the same common cold coronaviruses all the time. Certain viruses seem to often confer sterilizing immunity (total immunity), but many seem to just prepare us better for future infections, meaning we have less severe disease or none at all but we still get infected and it still replicates in our system, and some seem to never bring about immunity at all.

    Most of the other cases of re-infection I have heard the second case was less severe, but supposedly that was not the case with the second patient you mentioned, he apparently developed a more serious disease the second time around. Who knows why this is, there are some viruses that can actually cause more serious disease if you have some immune response from a previous infection/vaccination (antibody dependent enhancement), but I haven't heard any confirmation of that with this virus or this patient. Another speculation I heard on this case is that its possible this patient beat the infection with just his innate response or that it was confined to just his upper respiratory tract the first time, and the second time the viral infection reached his lower respiratory tract and/or achieved much higher infection and this lead to more severe disease as it was almost like it was the first infection for this guy.

    From the very beginning one of the end-games I have heard proposed for this virus was that it would become endemic and due to our partial immunity, it would join the ranks with the other common coronaviruses in being another cold causing virus. Who knows if that will be the case but it sounds plausible. I wonder is re-infection much more common than we think but just much more likely to be very mild that we don't even detect them?


  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh


    raind wrote: »
    Comments on both cases:

    First was a severely immunity compromised individual

    Second included this comment from a Harvard professor of epidemiology
    “Re-exposures are essential to build our immune system,” Mina wrote. “But like anything, when enough people get a re-exposure, there are going to be rare cases here and there that go awry and someone gets more sick the second time.”

    We are seeing cases of reinfection, and the pattern of them being rare but consistent looks like what I would expect to see with failing natural immunity.

    So, maybe people will have some number of months with natural immunity. But this doesn't imply that a vaccine response will be for that length of time also.


  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh


    DaSilva wrote: »
    I wonder is re-infection much more common than we think but just much more likely to be very mild that we don't even detect them?

    I would make it even simpler and say the pattern of reinfection is the same as the virus in the population now. It's the same virus.


  • Registered Users Posts: 9,795 ✭✭✭ raind


    igCorcaigh wrote: »
    We are seeing cases of reinfection, and the pattern of them being rare but consistent looks like what I would expect to see with failing natural immunity.

    So, maybe people will have some number of months with natural immunity. But this doesn't imply that a vaccine response will be for that length of time also.

    Vaccines for coronaviruses in cats are annual, and many vaccines require boosters to ensure lasting effects.

    I don’t think it looks like failing immunity, as pointed out, immunity is never binary and no virus exposure or vaccine ever offers 100% immunity


  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh


    Might have an impact on the monoclonal antibodies that are being used for therapy.


  • Registered Users Posts: 5,045 ✭✭✭ blindjustice


    One of the key questions in predicting the course of the COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is how well and how long the immune responses protect the host from reinfection. For some viruses, the first infection can provide lifelong immunity; for seasonal coronaviruses, protective immunity is short-lived.1
    In The Lancet Infectious Diseases, Richard L Tillett and colleagues describe the first confirmed case of SARS-CoV-2 reinfection in the USA.2 A 25-year-old man from the US state of Nevada, who had no known immune disorders, had PCR-confirmed SARS-CoV-2 infection in April, 2020 (cycle threshold [Ct] value 35·24; specimen A). He recovered in quarantine, testing negative by RT-PCR at two consecutive timepoints thereafter. However, 48 days after the initial test, the patient tested positive again by RT-PCR (Ct value 35·31; specimen B). Viral genome sequencing showed that both specimens A and B belonged to clade 20C, a predominant clade seen in northern Nevada. However, the genome sequences of isolates from the first infection (specimen A) and reinfection (specimen B) differed significantly, making the chance of the virus being from the same infection small. What is worrisome is that SARS-CoV-2 reinfection resulted in worse disease than did the first infection, requiring oxygen support and hospitalisation. The patient had positive antibodies after the reinfection, but whether he had pre-existing antibody after the first infection is unknown

    https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30783-0/fulltext


  • Registered Users Posts: 9,795 ✭✭✭ raind


    One of the key questions in predicting the course of the COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is how well and how long the immune responses protect the host from reinfection. For some viruses, the first infection can provide lifelong immunity; for seasonal coronaviruses, protective immunity is short-lived.1
    In The Lancet Infectious Diseases, Richard L Tillett and colleagues describe the first confirmed case of SARS-CoV-2 reinfection in the USA.2 A 25-year-old man from the US state of Nevada, who had no known immune disorders, had PCR-confirmed SARS-CoV-2 infection in April, 2020 (cycle threshold [Ct] value 35·24; specimen A). He recovered in quarantine, testing negative by RT-PCR at two consecutive timepoints thereafter. However, 48 days after the initial test, the patient tested positive again by RT-PCR (Ct value 35·31; specimen B). Viral genome sequencing showed that both specimens A and B belonged to clade 20C, a predominant clade seen in northern Nevada. However, the genome sequences of isolates from the first infection (specimen A) and reinfection (specimen B) differed significantly, making the chance of the virus being from the same infection small. What is worrisome is that SARS-CoV-2 reinfection resulted in worse disease than did the first infection, requiring oxygen support and hospitalisation. The patient had positive antibodies after the reinfection, but whether he had pre-existing antibody after the first infection is unknown

    https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30783-0/fulltext

    Second time this case has been mentioned in 12 hours so its not an additional case.

    Comment below is from a professor of epidemiology
    Re-exposures are essential to build our immune system,” Mina wrote. “But like anything, when enough people get a re-exposure, there are going to be rare cases here and there that go awry and someone gets more sick the second time.


  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh




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  • Registered Users Posts: 8,490 ✭✭✭ igCorcaigh




  • Registered Users Posts: 3,124 ✭✭✭ tobefrank321


    Still less than 10 cases of reinfection out of almost 40 million confirmed cases. Not something to be overly concerned with.


  • Registered Users Posts: 639 ✭✭✭ Thats me


    Still less than 10 cases of reinfection out of almost 40 million confirmed cases. Not something to be overly concerned with.


    Will be more. 30% of recovered patients do not produce antibodies for Corona at all. Virus mutating and these who got immune temporally are also in danger few months later. I'd guess low numbers are only because these who already had Covid just better protecting themselves than these who denies a danger because of their poor imagination.


  • Registered Users Posts: 1,498 ✭✭✭ SeaBreezes


    Im following this guy on twitter, caught my eye he has a phd in Tcell immunity so I wanted to see his thoughts on it.

    His own preference, is not to get it. He seems to think it ages Tcells and reinfection likely possible and each time more severe. It hasnt been a year yet. We wont know if reinfection is a general thing until next year.

    Though bergamo opening up its covid ward again doesnt bode well.


    https://twitter.com/fitterhappierAJ/status/1300709734618669057?s=20


  • Registered Users Posts: 639 ✭✭✭ Thats me


    SeaBreezes wrote: »
    and each time more severe.


    This is unlikely. Current death rate is much lower than we had in April. It can grow because IE run out of ICUs, but on present numbers it is MUCH lower than in April. Probably because most dangerous stains dying first, with their owners.


  • Registered Users Posts: 5,045 ✭✭✭ blindjustice


    Still less than 10 cases of reinfection out of almost 40 million confirmed cases. Not something to be overly concerned with.

    Its certainly not as simply as that. 10 have been checked and tested for each strain. That is certainly not something that is being checked routinely. Suggesting that its 10 out of 40 million is just wrong.


  • Registered Users Posts: 72,022 ✭✭✭✭ Atlantic Dawn


    Why is the government not encouraging those recovered infected to be a seperate designation of person in our country, they are recovered and should be treated like people above those who have not been infected, gold for the economy where social distancing required.


  • Registered Users Posts: 639 ✭✭✭ Thats me


    they are recovered and should be treated like people above those who have not been infected, gold for the economy where social distancing required.


    They can be more vulnerable than these who was not infected yet. They can be not fit to do their jobs because of post-covid syndrome. They can have no immunity developed. And even if they immune and healthy they still can passively help virus to spread.


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