# This could be bad: Hong Kong announces first confirmed reinfection case **URL:** \ **Category:** The Quarantine Zone\ **Tags:** covid-quarantine\ **Created:** [August 24, 2020, 3:06pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892 "2020-08-24T15:06:50Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [August 24, 2020, 3:06pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/1 "2020-08-24T15:06:50Z")
Stories on this are just coming out, so it’s unknown how widespread this will be if it is even confirmed by other sources. But, we appear to have the first confirmed case of a patient recovering from Covid19 and becoming reinfected. > **[Hong Kong reports first confirmed coronavirus reinfection](https://www.latimes.com/world-nation/story/2020-08-24/hong-kong-coronavirus-reinfection)** > > The man’s second SARS-CoV-2 infection was detected in an airport screening as he returned to Hong Kong from Europe. This could be very, very bad. Especially if your policy has been to ignore Coronavirus and hope that letting everyone get infected would lead to herd immunity – if this turns out to be a pattern rather than a fluke, you may have been burning lives at an empty altar. ---
**Author:** ![Lantern2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lantern2/32/3010_2.png) [@Lantern2](https://boards.straightdope.com/u/Lantern2)\ **Post date:** [August 24, 2020, 3:40pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/2 "2020-08-24T15:40:22Z")
Yes. Horrible news especially given this is a young, healthy person. Let’s hope this is rare and also that the vaccine gives more lasting immunity. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 24, 2020, 4:15pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/3 "2020-08-24T16:15:24Z")
FWIW SARS-CoV-2 would have to have been an exceptional germ to protect all from any subsequent infection. Susceptiblity to subsequent usually asymptomatic to mild infection occurring months to years after a first infection is probably a best case. No reason to expect any vaccine to do better, improbable to do as well … if it happens it potentially accomplishes it by way of less harms though. Vaccine or not this germ will highly probably be endemic in the future. ---
**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\ **Post date:** [August 24, 2020, 4:32pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/4 "2020-08-24T16:32:41Z")
> [@DSeid](#): > > endemic It’s one of those words I come across but wasn’t **exactly** sure of the meaning. > # endemic > > [adjective](https://www.merriam-webster.com/dictionary/adjective) > en·​dem·​ic | \ en-ˈde-mik > > ## Definition of _endemic_ > > 1a **:** belonging or [native](https://www.merriam-webster.com/dictionary/native#h1) to a particular people or country > > b **:** characteristic of or [prevalent](https://www.merriam-webster.com/dictionary/prevalent) in a particular field, area, or environment problems endemic to translation the self-indulgence endemic in the film industry > > 2 **:** restricted or [peculiar](https://www.merriam-webster.com/dictionary/peculiar#h1) to a locality or region endemic diseases an endemic species ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 4:37pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/5 "2020-08-24T16:37:30Z")
Immune responses are one of the most variable phenomena in all of biology. The fact that reinfection _can_ sometimes happen is not surprising or frightening. What matters is the _typical_ immune response. > [@Babale](#): > > …if this turns out to be a pattern rather than a fluke, you may have been burning lives at an empty altar. Sure, but why does a first confirmed case of reinfection 6 months into a pandemic imply to you that this is a common or typical outcome? ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 4:51pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/6 "2020-08-24T16:51:01Z")
> [@ThelmaLou](#): > > endemic The sense can sometimes be to emphasize that a disease is present in a subpopulation in some particular geographic area; but here the emphasis is more on the idea of some baseline _persistent_ constant level of infection, rather than sporadic. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [August 24, 2020, 4:55pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/7 "2020-08-24T16:55:32Z")
The article I saw first: > **[Hong Kong man becomes first patient to be reinfected with coronavirus,...](https://www.nbcnews.com/science/science-news/hong-kong-man-was-reinfected-coronavirus-researchers-say-n1237840?fbclid=IwAR2rcw7oSd5z0iDjOkk9sWhn3F4LFk1lAzvT5giRVevtbY9VMrUv76kOfXQ)** > > The finding suggests that some patients who recover from COVID-19 may have only short-lived immunity to reinfection. From what I read there, this is certainly not good news, but it’s neither as surprising nor as alarming as it seems to some of us. ---
**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\ **Post date:** [August 24, 2020, 5:35pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/8 "2020-08-24T17:35:26Z")
> [@Riemann](#): > > The sense can sometimes be to emphasize that a disease is present in a subpopulation in some particular geographic area; but here the emphasis is more on the idea of some baseline _persistent_ constant level of infection, rather than sporadic. 👍🏼 Thanks. I’m into nuance. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 6:00pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/9 "2020-08-24T18:00:53Z")
The more worrying data were that antibody titer often seemed to be low or zero in people who had been infected. This concern has been somewhat alleviated by the Swedish study suggesting that cell-mediated immunity may be more important than humoral immunity. And I think we know enough from preliminary trials to say that vaccines will work to some degree, and we don’t need a vaccine to be 100% effective to achieve herd immunity. But we’re really not far enough along with this to have statistically meaningful data on the typical response, and how exactly this will look at a population level. ---
**Author:** ![Jay\_Z](https://avatars.discourse-cdn.com/v4/letter/j/a3d4f5/32.png) [@Jay\_Z](https://boards.straightdope.com/u/Jay_Z)\ **Post date:** [August 24, 2020, 6:03pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/10 "2020-08-24T18:03:49Z")
According to the article, he DOESN’T have COVID-19 (the disease) although he is re-infected (with the virus) because his anti-bodies are fighting the infection. Also asymptomatic, despite a 9 day hospital stay. Nice paid vacation I guess. This is a tree falls in the forest issue at this point. I guess I am not going to care about re-infection if it doesn’t actually do anything to me. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [August 24, 2020, 6:13pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/11 "2020-08-24T18:13:31Z")
> [@Riemann](#): > > Sure, but why does a first confirmed case of reinfection 6 months into a pandemic imply to you that this is a common or typical outcome? Good question – because it takes time. You can’t be reinfected until you were infected, healed, had enough time pass for your immune system to let its guard down, and become reinfected. There wasn’t enough time for this to occur until now, multiple months into the pandemic. ---
**Author:** ![SmartAleq](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smartaleq/32/163_2.png) [@SmartAleq](https://boards.straightdope.com/u/SmartAleq)\ **Post date:** [August 24, 2020, 6:21pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/12 "2020-08-24T18:21:02Z")
> [@Jay\_Z](#): > > This is a tree falls in the forest issue at this point. I guess I am not going to care about re-infection if it doesn’t actually do anything to me. Because fuck everyone else you could be giving it to? I think we’re all gonna be wearing masks in public for quite a spell. ---
**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\ **Post date:** [August 24, 2020, 6:31pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/13 "2020-08-24T18:31:49Z")
> [@Jay\_Z](#): > > Also asymptomatic, despite a 9 day hospital stay. Nice paid vacation I guess. > > This is a tree falls in the forest issue at this point. I guess I am not going to care about re-infection if it doesn’t actually do anything to me. Gee, if cynicism were a vaccine, you’d be 100% protected. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 6:45pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/14 "2020-08-24T18:45:45Z")
> [@Babale](#): > > Good question – because it takes time. You can’t be reinfected until you were infected, healed, had enough time pass for your immune system to let its guard down, and become reinfected. There wasn’t enough time for this to occur until now, multiple months into the pandemic. Possibly. But this patient was first infected in April, not at the very start of the pandemic. There is always variation and outliers in immune response. A single case has no statistical significance, the fact that reinfection is _possible_ in some cases is not surprising. ---
**Author:** ![Jay\_Z](https://avatars.discourse-cdn.com/v4/letter/j/a3d4f5/32.png) [@Jay\_Z](https://boards.straightdope.com/u/Jay_Z)\ **Post date:** [August 24, 2020, 6:47pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/15 "2020-08-24T18:47:30Z")
It’s about the 1,000,000th clickbait article on COVID-19. Usually the contents have nothing to do with the headline. Which is why I hate them. If everyone can get COVID-19 again, but it’s a non-lethal version… that’s far different than the fear factor version. I don’t really care what viruses are in my body if they do nothing to me. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 7:13pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/16 "2020-08-24T19:13:19Z")
Here’s the BBC version of the story, including responses from experts. > **[Hong Kong reports 'first case' of virus reinfection](https://www.bbc.com/news/health-53889823)** > > Experts say no conclusions on immunity can be drawn from one patient - and larger studies are needed. > “This is a very rare example of reinfection,” said Brendan Wren, professor of microbial pathogenesis, at London School of Hygiene and Tropical Medicine… > > “It is to be expected that the virus will naturally mutate over time.” > > Dr Jeffrey Barrett, senior scientific consultant for the Covid-19 genome project at the Wellcome Sanger Institute, said: "Given the number of global infections to date, seeing one case of reinfection is not that surprising even if it is a very rare occurrence. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [August 24, 2020, 7:20pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/17 "2020-08-24T19:20:50Z")
I can’t tell from the reporting I’ve read: have they confirmed that the patient acquired the second infection from another person? Or could it be that his original infection has flared up? ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 7:23pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/18 "2020-08-24T19:23:10Z")
> [@Pleonast](#): > > have they confirmed that the patient acquired the second infection from another person? From the article linked in the OP: > Researchers at the University of Hong Kong used genomic sequence analysis to prove that he had been infected by two different strains. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 24, 2020, 7:34pm UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/19 "2020-08-24T19:34:38Z")
The fact that it’s a different strain (presumably a strain with a known set of mutations that was known to be circulating, removing the possibility that the mutations occurred _de novo_ in this patient) proving that it was a second infection. This may also mean that’s what happened in this patient’s immune system is not that his acquired immunity faded, but that his immune system had learned to recognize and respond to an epitope on the first strain that mutated and was just not present in the second strain. This possibility has rather different implications than a lack of persistence in acquired immunity to the original strain. If it turned out to be common, it might mean that the way this plays out is similar to influenza vaccination. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 25, 2020, 1:56am UTC](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892/20 "2020-08-25T01:56:57Z")
Thing is that reinfections when they occur, however often it turns out to be over whatever time course, may be more commonly asymptomatic like this one, or very mild. May be hard to find them. Not many asymptomatic people previously infected being tested. Unknown how transmissible they are either. [Next page](https://boards.straightdope.com/t/this-could-be-bad-hong-kong-announces-first-confirmed-reinfection-case/918892.md?page=2)