Off topic, but related enough that I feel its relevant to mention:
I learned this week that many blood donation and plasma centers [1][2] are doing Coronavirus antibody tests for anyone* that donates right now.
I've heard a lot of people in my social / online circles comment how they wish they knew whether or not they had antibodies. Seems like a great way to find out.
"I've heard a lot of people in my social / online circles comment how they wish they knew whether or not they had antibodies"
What people need to realize is that the important questions are not whether you've got antibodies but:
1 - whether you'll sick when you're exposed to the virus again
2 - how sick you'll get the next time around
No one knows the answers to these questions yet, and we also don't know how antibodies bear on the answers to these questions.
It is possible that even with antibodies you'll still get sick if you're exposed to the virus (as we know is the case for some other diseases), and even if antibodies play some role in how sick you'll get it's possible that (again, as is the case with some diseases) repeated exposure to the virus will cause even greater illness than the first time around.
People shouldn't be assuming that having antibodies means they're immune.. we just don't know enough yet to say whether that's true or not.
Even if it is true, there might be a certain level of antibodies that are required to have a certain level of immunity, and we don't know yet what level of antibodies are necessary, nor the kind of antibodies necessary,
Finally, even if antibodies do grant immunity, we don't know how long that immunity would last, nor if such immunity varies from person to person for some not yet known reason.
If people could get reinfected we would have heard of more of those cases by now. We can be pretty sure that it confers several months of immunity at minimum.
A few days ago spanish media reported that one of the latest outbreak in Lleida affected a residence. They tested all inmates in the residence with PCR, and found 8 positives. 5 of these 8 had COVID-19 a few months ago with the first wave (I guess march / april).
From all we know from other viruses you might get reinfected but with a very high probability you won’t get very sick. Also, note that immunity is not only AB induced. You have other immune components like T Cells in your body patrolling and reacting to pathogen. Otherwise everybody would have gotten really sick from SARS2 which is obviously not the case.
I don't believe the virus is known to behave like this to a very high probability. It's unknown but possible the virus behaves like dengue fever and gets worse the second time.
> It's unknown but possible the virus behaves like dengue fever and gets worse the second time.
That's not how dengue works. There are four variants of the dengue virus, and it gets worse the second time only if it's a different variant. Quoting Wikipedia (https://en.wikipedia.org/wiki/Dengue_virus):
"Developing a vaccine against the disease is challenging. With four different serotypes of the virus that can cause the disease, the vaccine must immunize against all four types to be effective. Vaccination against only one serotype could possibly lead to severe dengue hemorrhagic shock when infected with another serotype due to antibody-dependent enhancement. When infected with dengue virus, the immune system produces cross-reactive antibodies that provide immunity to that particular serotype. However, these antibodies are incapable of neutralizing other serotypes upon reinfection and actually increase viral replication."
There are variants of COVID-19, but there is no evidence that the variations are of any biological significance.
There is no evidence that the variations change how infectious the virus is or how severe the illness is or how often people die from it or anything else.
Certainly I am not suggesting there is evidence, I am just saying it too early to dismiss the possibility . There is no concrete evidence saying it won't happen either.
Seasonal Flu does mutate fast enough that any immunity is typically seasonal, so it unreasonable to consider the possibility of mutation
IIRC, Dengue has 4 different strains. When you get reinfected with the same strain, then you are good. Getting one of the other strains is the problematic case.
As someone who was likely exposed back in March (no tests available at the time, and antibody test now is showing negative, which I don’t believe), I will anecdotally mention a few observations:
1. While you don’t get “really” sick again, you do “feel it” when re-exposed. Specifically I noticed diarrhea and a being a bit “off” on two separate instances where I believe I was Re-exposed.
2. I am 90% certain that even with immunity you remain a carrier when Re-exposed. I don’t know how much of a carrier, but just my strong suspicion (and why I have been extra careful when I have felt “off”)
Would love more medical data to back my hypothesis/observations/thoughts, but thought I would mention it.
Mate, no offense, but this is all personal opinion and personal guesses while you’ve actually tested negative!
If I were you, have a bit less certainty in your own guesses. Next to that, every person has a different set of symptoms and experiences, your experiences aren’t all that relevant.
Completely agree, and have been extremely careful. I won’t go into the basis of my belief (which included 103.7 fever).
My main point, and why I said anything at all is this: Even if you get infected, and get through it, there is no Scientific evidence to believe you are “in the clear” now.
Hoping that is an “add” rather than a subtract from the conversation.
I recommend reading this blog post [1] about the unknowns of immunity. Antibodies are only part of the immunity picture, as this tweetstorm [2] concisely explains.
There are a lot of not-altogether-scientific reasons. Gay people can’t give blood. If I recall correctly British people can’t either because of Foot and Mouth disease, something that happened in the 90s.
They are based on reasons that are statistically founded in some way because not everyone's blood can be tested as extensively as anyone would like, so reducing risk factors helps. I can't speak for every country but this is at least the case for the ones I've lived in and donated in.
Also, it's no longer true in many (most?) places that "gay people" can't give blood, as the distinguishing factor nowadays is usually recent sexual activity.
Note that "recent at-risk sexual activity" specifically means (among other things) a man engaging in sex with another man in the past 12 months (at least that's the case in Australia[1]).
Practically speaking this means that the vast majority of gay men cannot donate blood -- even if the criteria don't explicitly say the words "gay men cannot donate blood". Don't get me wrong, I agree that there are purely statistical reasons why these restrictions are in place (blood banks aren't out looking for excuses to reduce their supplies) -- but it's really not accurate to say that it's no longer the case that gay men cannot donate blood.
I also hasten to note that having many sexual partners is not considered "at-risk sexual activity" (though there are some exceptions), while two monogamous men in a homosexual relationship having sex is always considered as being "at-risk".
> In 2015, the US Food and Drug Administration (FDA) relaxed its guidance but still required men to abstain from sex with another man for at least a year before they could give blood, a policy that the the American Public Health Association said was “not based in science”.
Can confirm: I'm not allowed to give blood in Australia because of the small risk (with a potentially very bad downside if it manifests) that I'm infected with mad cow disease, due to living up in the UK in the 90s.
They still let me sign up to the organ donor list though.
Edit: foot and mouth disease was a decade later. I don't believe it's a problem in humans?
I learned this week that many blood donation and plasma centers [1][2] are doing Coronavirus antibody tests for anyone* that donates right now.
I've heard a lot of people in my social / online circles comment how they wish they knew whether or not they had antibodies. Seems like a great way to find out.
[1] https://www.redcrossblood.org/donate-blood/dlp/covid-19-anti...
[2] https://www.lifeservebloodcenter.org/donate/recovered-covid-...
* Probably not literally anyone, but it sounds like they are giving them out pretty freely.