Can I safely mingle with a couple who have already had Covid?
January 3, 2021 2:29 PM
Some good friends recently contracted Covid. Both were pretty sick and the husband was intubated. They want to visit in March. Is there a safe way to do this?
We don't want to offend them, but also from my limited knowledge the likelihood of reinfection is low.
We don't want to offend them, but also from my limited knowledge the likelihood of reinfection is low.
I am worried that they may get reinfected, and am looking for some science to prove or disprove that notion. The last thing I saw on this was an epidemiologist on TikTok.
posted by mecran01 at 2:33 PM on January 3, 2021
posted by mecran01 at 2:33 PM on January 3, 2021
From the Lancet:
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 (table).
sauce
posted by mecran01 at 2:35 PM on January 3, 2021
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 (table).
sauce
posted by mecran01 at 2:35 PM on January 3, 2021
From Dear Pandemic on November 18, 2020:
If I already recovered from Covid-19 infection, can I be sure I won’t get it again or pass it to others?posted by lapis at 2:36 PM on January 3, 2021
A: No. Evidence on the longevity and strength of the immune system response to SARS-CoV-2 remains inconclusive.
Previous infection does not give you an “immunity passport”. All individuals should continue to follow SMART precautions, particularly during the holiday season.
Here is what we know to date.
Antibody testing alone is an insufficient measure of immunity. Antibody testing is available in many settings of variable quality. The presence of antibodies in the blood should not be considered immunity. While some individuals have detectable levels of antibodies months after infection, others do not. The amount and length of time antibodies are present give only a partial picture of the immune response.
Immune response involves antibodies, B cells, and T cells. We need to understand how all three respond to SARS-CoV-2 infection over periods of months to years to determine the strength and longevity of an immune response following natural infection. New results from a not yet peer-reviewed study of individuals infected with SARS-CoV-2 followed over months suggests a robust immune response, though was done among a small sample of individuals with variation in the immune responses detected across individuals. This study is very welcome good news that immunity would protect you from severe disease in the future. These results *DO NOT* change safety practices among individuals who have been infected and recovered as it remains unclear if the immune response protects from reinfection and spread to others.
SARS-CoV-2 infection results in variable immune response from person to person. For this reason, not every person infected will have comparable immunity to potentially protect them if they are re-exposed to the virus. Immunity resulting from vaccination is studied closely to determine how much of the population is likely to develop an adequate immune response to prevent illness AND how long that response lasts. It’s insufficient at this time to depend on previous infection as protection from reinfection and further spread of the virus. Promising ne evidence (phew!) suggests long lasting immune response after Covid-19 infection AND effective vaccines are in the pipeline. For now, everyone should be following the same guidelines – mask up, restrict networks, and prepare for brighter days on the horizon.
It's impossible to know what the world will look like in March. Reinfections so far seem to be rare but we don't really know the full picture, or whether new variants will have emerged by then. The safest thing is to plan for a March visit the way you would plan for a visit today:
Best option: Don't do it
2nd best option: Everyone fully quarantines for two weeks prior to the visit (on their end, isolating before the flight and then before visiting you) and then for two weeks after it too. During the visit everyone should remain at home as much as possible and observe masking and handwashing and distancing as much as possible.
Doesn't sound super fun huh? Yeah that's why the best option is don't do it.
posted by We put our faith in Blast Hardcheese at 2:39 PM on January 3, 2021
Best option: Don't do it
2nd best option: Everyone fully quarantines for two weeks prior to the visit (on their end, isolating before the flight and then before visiting you) and then for two weeks after it too. During the visit everyone should remain at home as much as possible and observe masking and handwashing and distancing as much as possible.
Doesn't sound super fun huh? Yeah that's why the best option is don't do it.
posted by We put our faith in Blast Hardcheese at 2:39 PM on January 3, 2021
(If I have misinterpreted the question and they don't in fact have to travel, or can travel by car with no stops, then that does change the quarantine math pre-visit a bit; they would just need to quarantine for two weeks prior to visiting you.)
posted by We put our faith in Blast Hardcheese at 2:41 PM on January 3, 2021
posted by We put our faith in Blast Hardcheese at 2:41 PM on January 3, 2021
I think your Lancet link is the most authoritative answer available to your question (i.e. can they get reinfected and will that harm them) and is very recent. As you saw there, the article is all questions and very few answers.
It does indeed show several cases where someone recovered and was reinfected, and some cases where the reinfection caused a serious disease. As covered in that article, no-one yet knows whether that is a general rule or a rare case.
posted by richb at 2:53 PM on January 3, 2021
It does indeed show several cases where someone recovered and was reinfected, and some cases where the reinfection caused a serious disease. As covered in that article, no-one yet knows whether that is a general rule or a rare case.
posted by richb at 2:53 PM on January 3, 2021
Millions of people worldwide have had COVID. If reinfection were common we would know by now. A handful of instances does not a high risk make.
It’s fine.
posted by Huffy Puffy at 3:27 PM on January 3, 2021
It’s fine.
posted by Huffy Puffy at 3:27 PM on January 3, 2021
It is not yet clear how long people are shedding the virus after they’ve been infected.
posted by iamkimiam at 3:33 PM on January 3, 2021
posted by iamkimiam at 3:33 PM on January 3, 2021
It is not yet clear how long people are shedding the virus after they’ve been infected.
Look, I'm not a doctor, but the science is pretty clear on this. People are infectious for weeks at most : "replication-competent virus has not been recovered after 10 days following symptom onset... replication-competent virus was not isolated 3 weeks after symptom onset".
The science on re-infection is still emerging. It seems like it's uncommon, but to actually prove it, you need to genotype the person at both infections. It seems to me that if people were often getting reinfected a couple months after infection we would have noticed it by now, but that's not the same thing as actually having scientific evidence.
posted by BungaDunga at 4:05 PM on January 3, 2021
Look, I'm not a doctor, but the science is pretty clear on this. People are infectious for weeks at most : "replication-competent virus has not been recovered after 10 days following symptom onset... replication-competent virus was not isolated 3 weeks after symptom onset".
The science on re-infection is still emerging. It seems like it's uncommon, but to actually prove it, you need to genotype the person at both infections. It seems to me that if people were often getting reinfected a couple months after infection we would have noticed it by now, but that's not the same thing as actually having scientific evidence.
posted by BungaDunga at 4:05 PM on January 3, 2021
The closest thing to evidence is probably stuff like this (from the same page I linked): "The risk of reinfection may be lower in the first 3 months after initial infection, based on limited evidence from another betacoronavirus (HCoV-OC43), the genus to which SARS-CoV-2 belongs... Based on what we know from other related human coronaviruses, people appear to become susceptible to reinfection around 90 days after onset of infection. To date, reinfection appears to be uncommon during the initial 90 days after symptom onset of the preceding infection" but it notes that "Correlates of immunity to SARS-CoV-2 infection have not been established."
So, nobody knows for sure.
posted by BungaDunga at 4:08 PM on January 3, 2021
So, nobody knows for sure.
posted by BungaDunga at 4:08 PM on January 3, 2021
Safety questions aside, I would perhaps point out to them how unlikely it is that you'll be able to predict what things are like in March and planning anything that far in advance isn't a great idea. Maybe suggest that you come back together in late February to see how things are, at which point we may have a better idea about the rates of reinfection, as well as vaccinations etc.
posted by fight or flight at 4:15 PM on January 3, 2021
posted by fight or flight at 4:15 PM on January 3, 2021
We have no way of knowing how much of the "recovered" population is getting reinfected but are either asymptomatic (but still contagious) or assume the new infection is just another surge in long-tail symptoms/secondary disease as a result of the original damage and don't seek out any additional treatment or confirmation. Testing is still difficult to obtain in many places and is very unevenly distributed within communities, we just don't have very good data and probably aren't gonna start knowing more until March or April at the earliest (if ever).
I wouldn't put money into nonrefundable plane tickets or anything. I don't think this is a decision you're going to be able to make until at best about two weeks before the intended visit date.
posted by Lyn Never at 5:05 PM on January 3, 2021
I wouldn't put money into nonrefundable plane tickets or anything. I don't think this is a decision you're going to be able to make until at best about two weeks before the intended visit date.
posted by Lyn Never at 5:05 PM on January 3, 2021
Not sure this will help, but I just tell people that I'm sorry and am probably being overly cautious, but it would make me too nervous and I'd have trouble relaxing, and I'd rather save the fun of a visit with them until a time when I could really enjoy it. The only people I'd hang out with are people who are quarantined at the same level as we are most of the time (no outside contact aside from package delivery and curbside grocery pickup), who I could see without any of us getting exposed in the process (e.g., via airplanes or public restrooms). But yeah, that might be me being overly cautious.
posted by slidell at 5:42 PM on January 3, 2021
posted by slidell at 5:42 PM on January 3, 2021
I'm just a lab scientist who reads things, but the evidence for reinfection says it's at a rate of something like a handful per million, and that natural immunity is quite reliable for a few months at least. Your risks to them and from them are on the level of plane accident.
So I would do this without hesitation, and I have not had a haircut since March let alone eaten around anyone else. The risks are much more concentrated in how you travel (which I would not do) and without further detail I cannot comment there.
posted by Dashy at 6:21 PM on January 3, 2021
So I would do this without hesitation, and I have not had a haircut since March let alone eaten around anyone else. The risks are much more concentrated in how you travel (which I would not do) and without further detail I cannot comment there.
posted by Dashy at 6:21 PM on January 3, 2021
And if they wanted to travel to me to visit, I'd have then change and shower when they arrive, but otherwise welcome them with open arms.
posted by Dashy at 6:28 PM on January 3, 2021
posted by Dashy at 6:28 PM on January 3, 2021
Personally I've categorized people who've had it as "less likely" vectors, meaning more or less that I'm willing to buy off a mitigation measure in interactions with them.
But my confidence in that judgment is pretty limited, so I'm wary of buying off more than one mitigation measure.
And I'm also wary of conclusions like this:
Millions of people worldwide have had COVID. If reinfection were common we would know by now.
It seems to me that depends heavily on whether a reinfection is likely to be symptomatic. If it's not, how would those reinfected even be prompted to check and report leading to statistics we could be confident in?
And we *do* know that many are asymptomatic and contagious when first infected, so it seems plausible enough many would be on subsequent infections. Maybe even likely that they'd be asymptomatic during an entire subsequent infection course if the immune response moderates symptoms.
And that doesn't speak to questions like how long immune response lasts, or whether people can harbor/re-seed a load they've picked up from the environment even if they don't get infected.
I'm far from an expert and welcome correction of misconceptions I may be displaying here, but AFAICT it's not as simple as "we can be confident that people who got better are uninfectable and can't spread it."
posted by wildblueyonder at 7:49 PM on January 3, 2021
But my confidence in that judgment is pretty limited, so I'm wary of buying off more than one mitigation measure.
And I'm also wary of conclusions like this:
Millions of people worldwide have had COVID. If reinfection were common we would know by now.
It seems to me that depends heavily on whether a reinfection is likely to be symptomatic. If it's not, how would those reinfected even be prompted to check and report leading to statistics we could be confident in?
And we *do* know that many are asymptomatic and contagious when first infected, so it seems plausible enough many would be on subsequent infections. Maybe even likely that they'd be asymptomatic during an entire subsequent infection course if the immune response moderates symptoms.
And that doesn't speak to questions like how long immune response lasts, or whether people can harbor/re-seed a load they've picked up from the environment even if they don't get infected.
I'm far from an expert and welcome correction of misconceptions I may be displaying here, but AFAICT it's not as simple as "we can be confident that people who got better are uninfectable and can't spread it."
posted by wildblueyonder at 7:49 PM on January 3, 2021
Is there a safe way to do this?
Yes! Spend time together outdoors, or in an extremely well-ventilated area and masked.
There's a lot of unknowns to questions about reinfections, and everybody feels different about risk and probability. So if you want to have a safe visit, just stick to the common sense pandemic safety behaviors.
posted by entropone at 12:25 PM on January 4, 2021
Yes! Spend time together outdoors, or in an extremely well-ventilated area and masked.
There's a lot of unknowns to questions about reinfections, and everybody feels different about risk and probability. So if you want to have a safe visit, just stick to the common sense pandemic safety behaviors.
posted by entropone at 12:25 PM on January 4, 2021
>>Millions of people worldwide have had COVID. If reinfection were common we would know by now.
It seems to me that depends heavily on whether a reinfection is likely to be symptomatic.
Since wildblueyonder asked for assumptions to be challenged: for asymptomatic reinfection to be a problem in this scenario, you'd have to have a -wildly- higher rate of asymptomatic infection the 2nd time. For example, the evidence to date suggests reinfection at a handful per million. For asymptomatic reinfection to be a problem, you'd need hundreds per million to be asymptomatic and reinfected -- very, very different from the virus's initial behavior. There is just very little evidence, despite a great deal of interested watching from the medical community, that for reinfection, only a few get sick, but hundreds more are asymptomatic. You could imagine a wild scenario in which this is true, yes, but it's really at the level of conspiracy theory or plane crashing. These visitors are very much likely safe.
And it goes against the basics. Being immune means your system recognizes & prevents the virus from replicating. The virus has to replicate (copy itself over a gazillion times) in order for you to spread it back out, whether you're symptomatic or not. All the evidence so far says that for at least a few months, the immune system recognizes the virus and prevents it from replicating at all, for all but a very few of millions of people.
While it is true that the only way to definitively know would be to PCR-test and sequence every survivor every day, it's really quite quite quite unlikely.
Give the poor ex-intubated recovered person the hug they deserve.
posted by Dashy at 1:17 PM on January 4, 2021
It seems to me that depends heavily on whether a reinfection is likely to be symptomatic.
Since wildblueyonder asked for assumptions to be challenged: for asymptomatic reinfection to be a problem in this scenario, you'd have to have a -wildly- higher rate of asymptomatic infection the 2nd time. For example, the evidence to date suggests reinfection at a handful per million. For asymptomatic reinfection to be a problem, you'd need hundreds per million to be asymptomatic and reinfected -- very, very different from the virus's initial behavior. There is just very little evidence, despite a great deal of interested watching from the medical community, that for reinfection, only a few get sick, but hundreds more are asymptomatic. You could imagine a wild scenario in which this is true, yes, but it's really at the level of conspiracy theory or plane crashing. These visitors are very much likely safe.
And it goes against the basics. Being immune means your system recognizes & prevents the virus from replicating. The virus has to replicate (copy itself over a gazillion times) in order for you to spread it back out, whether you're symptomatic or not. All the evidence so far says that for at least a few months, the immune system recognizes the virus and prevents it from replicating at all, for all but a very few of millions of people.
While it is true that the only way to definitively know would be to PCR-test and sequence every survivor every day, it's really quite quite quite unlikely.
Give the poor ex-intubated recovered person the hug they deserve.
posted by Dashy at 1:17 PM on January 4, 2021
In a few months when vaccination is common, will you be comfortable mingling with a couple who've had their vaccine shots?
I'll bet everyone's answer is Yes.
The vaccine is 5% ineffective, whereas the reinfection rate for COVID-19 survivors is much smaller than that -- especially for "pretty sick" cases who had to build up a hefty pile of antibodies to fight it off.
posted by Harvey Kilobit at 8:38 PM on January 4, 2021
I'll bet everyone's answer is Yes.
The vaccine is 5% ineffective, whereas the reinfection rate for COVID-19 survivors is much smaller than that -- especially for "pretty sick" cases who had to build up a hefty pile of antibodies to fight it off.
posted by Harvey Kilobit at 8:38 PM on January 4, 2021
The vaccine is 5% ineffective
This makes it sound like the vaccine doesn't work in 5% of instances, which is absolutely not true, and I think it's worth being extremely clear about what this does and does not mean.
Initially, a vaccinated group of people will experience a case rate 1/20th that of a comparable group of unvaccinated people. And then, with widespread vaccination, the case rates in both groups will go down.
posted by entropone at 5:55 AM on January 5, 2021
This makes it sound like the vaccine doesn't work in 5% of instances, which is absolutely not true, and I think it's worth being extremely clear about what this does and does not mean.
Initially, a vaccinated group of people will experience a case rate 1/20th that of a comparable group of unvaccinated people. And then, with widespread vaccination, the case rates in both groups will go down.
posted by entropone at 5:55 AM on January 5, 2021
All of these discussions relate to one's personal risk tolerance. In the real world we cannot wait for certainty before we do what we need to do in life. And each person has his or her own calculus to make.
If I get Covid, I will probably not get it again within the next year. Like other viruses, it will probably mutate over time and there could be reinfections further down the road, though they may not be as dangerous given the immunity deriving from the first infection. I personally prefer to base my decisions on probabilities rather than possibilities and mysterious "unknowns." You may disagree.
posted by yclipse at 8:29 AM on January 5, 2021
If I get Covid, I will probably not get it again within the next year. Like other viruses, it will probably mutate over time and there could be reinfections further down the road, though they may not be as dangerous given the immunity deriving from the first infection. I personally prefer to base my decisions on probabilities rather than possibilities and mysterious "unknowns." You may disagree.
posted by yclipse at 8:29 AM on January 5, 2021
In a few months when vaccination is common, will you be comfortable mingling with a couple who've had their vaccine shots?
I'll bet everyone's answer is Yes.
No. While vaccines prevent someone from getting serious symptoms, it's not yet clear whether vaccinated people can still transmit the disease.
posted by slidell at 4:28 AM on January 6, 2021
I'll bet everyone's answer is Yes.
No. While vaccines prevent someone from getting serious symptoms, it's not yet clear whether vaccinated people can still transmit the disease.
posted by slidell at 4:28 AM on January 6, 2021
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Can you clarify what you are worried about?
As I understand it, once they have recovered then they will not be infectious, if you are worried about them passing it to you. They are likely immune, but the evidence is not 100% clear on that, if you are worried about you passing it to them.
posted by richb at 2:31 PM on January 3, 2021