TBD

This is the only evidence (to my knowledge) that you may be infected twice, but it is a really bad example. If you've seen living conditions on a Navy ship, you wouldn't be surprised to know how quickly any illness can spread. While I don't doubt these sailors were sick, it is entirely possible they had a regular cold (common when pulling in to a new port) combined with a faulty test.

I'm not aware that there's any scientific evidence that you can be infected twice. In fact, leading health experts believe the contrary.
I am, however, aware of many many many reports that the tests are really inaccurate.

(Strikethrough mine)

Seph87

At this point reinfection on a large scale is a statistical impossibility. There are millions of recovered people worldwide - if even 1% of them got reinfected, we would have seen tens of thousands of reinfections by now. Especially in places like NYC or Northern Italy where the prevalence of the virus was very high.

So either these examples we see are some sort of edge case driven by uncommon circumstances (e.g. an immune system disorder) or they are being driven by testing error. Either way it's not something that's worth worrying about when it comes to setting public policy or making large scale decisions.

wco81

Probably need to see if there are large number of infections if we get through the winter. So lets see in January or February.

knownothing

There are lots of cases from Italy, China, US etc. "leading" health experts do not believe the contrary > they believe not enough is known. Other corono virus's do not provide long term immunity. Many other virus's do not provide immunity. cf https://www.webmd.com/lung/coronavir...-reinfection#1

fransknorge

This should be a fairly fact based forum. The Sun as a source is really not up to the standard.

The argument is time. COVID-19 research is very fast (too fast one can argue) and right now there is not enough research to answer those questions. We know a few things: there is T-Cell after recovery, there is a degree of cross-immunity with common cold coronaviruses (common cold coronaviruses immunity efficiency is measured in months). We do not know anything about the length of the immunity, we do not know if the presence of antibodies means a strong immunity.
My guess: this will not happen this year.
https://www.sciencedirect.com/scienc...74761320301813
https://www.thelancet.com/action/sho...2820%2930985-5
https://www.cell.com/cell/pdf/S0092-...showall%3Dtrue

Seph87

Answering the immunity question has two steps:

1. Does being infected grant immunity to the virus?
2. If yes, how long does immunity last?

My point is that based on the statistics #1 is essentially guaranteed at this point. If there was no immunity granted we would have seen tens of thousands reinfected in places like NYC or Lombardy. Medical professionals would be getting sick over and over. So now the question becomes, "how long does immunity last?" which unfortunately we just have to wait and see. It could be months, it could be years, it could be forever.

Khabibul35

Thread has been dead for a while but I feel like there has been a lot more knowledge developed on COVID-19 lately and it's worth having this discussion again based on more current data.

... omeone who's had Covid, and having been tested during the illness with a PCR test and then had an IGG antibody test and thus fairly reasonably aware of my status, I find it a bit difficult to understand why I'm seen a risk when medical tests show that it's 99.9% likely that I'm actually not. It's also a bit weird to me that things like going outside the home are still seen as risky behavior on my part by a lot of people and also why I'm legally barred from activities that wouldn't be unsafe at all, like travel, socializing, etc.

I know immunity passports have negative aspects and in some ways create social tiers, but at the same time it does seems to support the idea that some people are immune and I wonder why we keep going against science and restrict people's activities for the sake of the individual's and society's safety when that doesn't benefit the individual or society in actuality.

Any thoughts?

fransknorge

How long does the immunity last ?

TBD

Please confirm you have a professional medical or public health background and/or add a reference to which "science" you think supports you here.

To my knowledge, but I am not a medical expert, antibodies does not mean you cannot infect others. Also, the length of immunity is still in question as the previous post implies.

Misco60

The vast majority of people - the uninfected and possibly the recovered/immune - would pose no risk to others in any social situation.

However, without being able to easily identify those who do pose a risk it is sensible - no matter how inconvenient and undesirable - to place restrictions on the whole of society. It's about looking after everyone, not just ourselves.

Khabibul35

Well, I tested positive with PCR for the virus, so pretty likely I had it. Furthermore, it's been over a month without symptoms and antibody test confirms I've had an immune response to it. There are of course no guarantees, but based on how rare reinfection is (12 reinfections out of 45 million cases, source below) that's pretty good evidence to laying down a claim to say that at least for 3 months after you're immune based on our best knowlege.

Now I understand why one might still oppose it, as Misco60 mentioned, maybe there are just too many obstacles to reliably create such systems. But what I find odd is that people aren't even discussing the possibility of doing things differently, even when scientific evidence supports the idea of at least short-term immunity. And not only that, I find the abundance of overcautious social shaming for my wanting to go outside as being "reckless" even if I'm following the rules/laws but just going outsie somewhat more often than the average person when I don't currently pose a risk to others. I do get the idea that we need to keep vigilant to keep the pandemic under control, it's totally fair for everyone to do their part an I did so by pretty much never leaving the house for several months except to get groceries, but I don't see why I now need to continue the same approach. IMO - one's actions should reflect the best supported science as much as possible, and on a larger scale as a society we should also seek to do the same.

https://www.cnet.com/health/if-you-a...t-reinfection/

fransknorge

Basically for what you propose we need to have a very low virus circulation. Currently this is not the case and this is by far the first, second, third, fourth ... priority to tackle before thinking about immunity passport for travel (which have their own issues in itself such as how do you deal with immunocompromised people ? How do you deal with declining IgG antibodies ?)

Khabibul35

So the EU just this week announced that it is considering issuing vaccine certificates as means to reintroduce travel within the zone.

What I find ironic is how thoroughly hated the idea was when people mentioned "immunity passports", which people though was an unjustly tiered system or not techinically feasible. What changed and are they really going to make it so someone who's tested positive for antibodies from being previously infected not being able to hold someone who has antibodies from a vaccine? Seems odd to me.

jmastron

First, creating an incentive to catch and spread a deadly disease is fairly bad public policy. And for the same reason, I doubt we'll see "vaccine passports" allow for significant privileges until the vaccines are relatively widely available to most people. Creating an incentive to push past others in line or to forge documents is also not a great idea (on the other hand, promising some future benefits is a good way to incentivize people to get it when it's their turn).

And second, at least getting a vaccine is a fairly standard thing -- proving you have "immunity" (and we still don't know what that means, how long it lasts, etc) from having had COVID is not. It relies on either fairly inaccurate antibody tests (which led to some of the politicized claims early on of much higher than credible percentages in some areas having had it), or records of having been tested for or diagnosed with it which are much harder to standardize into a status.

But I wouldn't be surprised once numbers are a LOT lower (due to vaccines in the population) if some form of "I can prove I had it" was allowed in some cases as an alternative to a vaccine certificate. It's not too early to talk about, but it's still way to early for any of this to be deployed yet anyway.

doctoravios

It is interesting to revisit this topic 8 months on. The one major change which will affect this is the emergency of immune-escape variants which likely means the vaccines will be changing at some point this year. This makes it much harder to justify the notion of "immunity passports" (and logistical difficulties in whether they would distinguish between "old" and "new" vaccines) although I am sure some countries will attempt it.

If COVID-19 had been more like measles (i.e. with a highly efficacious vaccine which is impervious to immune escape variants conferring life-long immunity) then there would be a lot more to be gained from this approach. It will be interesting to revisit this topic in 6 months from now when transmission rates have dropped, we better understand the new variants, and there are more vaccines available.