Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

reuters.com

Post reply on HN
Print view View original

111–120 of 544 posts

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#111

Post by carey »

koyote wrote: post #91
kian wrote: post #55

Earlier quoted context omitted.

Only if they form antibodies. Studies have been suggesting that people who get it in asymptomatic form are not all forming antibodies - leaving them wide open to be future communicators of the disease.

Wouldn't that mean that a vaccine is close to impossible? My layman understanding is that a vaccine relies on the body creating antibodies.

It’s possible and desirable for a vaccine to stimulate antibody production where a “natural” infection would not, which is one of the things that will be tested during their development. An extreme example is infection with the tetanus-causing bacterium clostridium tetani, which doesn’t provide natural immunity at all.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#112

Post by eindiran »

koyote wrote: post #91
kian wrote: post #55

Earlier quoted context omitted.

Only if they form antibodies. Studies have been suggesting that people who get it in asymptomatic form are not all forming antibodies - leaving them wide open to be future communicators of the disease.

Wouldn't that mean that a vaccine is close to impossible? My layman understanding is that a vaccine relies on the body creating antibodies.

A known failure mode of vaccines is if the person who is being vaccinated lacks the right B cells for creating antibodies matching the antigens on the surface of a pathogen. If the B cells a person has lack the right B Cell receptors, they can't generate the correct antibody response to an antigen, because they can't bind with/identify an antigen in the first place. Additionally, they may lack a sufficient number of antigen naive T cells, which haven't yet become differentiated as T memory cells and effector T cells.

But that doesn't mean that it is impossible to create a vaccine: this problem exists already for successful vaccines. For example, the Hepatitis B vaccine has a relatively high failure rate, but is still provides immunity 90+% of the time. It just means that some smallish percentage of the people you vaccinate aren't actually contributing to population immunity.

See below for more info:

https://en.wikipedia.org/wiki/B_cell

https://en.wikipedia.org/wiki/Memory_B_cell

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3760154/ --> this one is particularly good. A lot of good info in here on how vaccination and "memory" interact.

https://www.sciencedirect.com/science/article/pii/S0264410X0...

EDIT: this one covers the major routes of vaccination failure --> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4962729/#!po=60...

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#113

Post by Gibbon1 »

feral wrote: post #90
ivoras wrote: post #40

Adding to that, Netherlands' study of antibodies in blood donors' samples shows about 10x difference between the number of reported / tested cases and actual cases in the general population (i.e. a lot more people got it and were not sick): https://www.nytimes.com/reuters/2020/04/16/world/europe/16re... ?

The Netherlands has 3.3k deaths vs 29k confirmed cases, which would give a CFR of ~10% I.e. the Netherlands aren't testing much. A 10x reduction there brings it back to the CFR range we see in countries with bigger testing programs. I'm not a specialist but have been following this for a while, and have yet to see evidence the IFR for this isnt around 0.5-1% (assuming decent healthcare). That's what we saw in the Dia…

My current bet is younger healthy people are more likely to be asymptomatic. And older people much less so. Theodore Roosevelt with likely a young population, most are asymptomatic. Diamond Princess much older population most are symptomatic.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#114

Post by usaar333 »

ashtonkem wrote: post #102
usaar333 wrote: post #100

Earlier quoted context omitted.

But can you not compare the ratios between age groups? That's all I'm doing here - showing deaths have a higher age correlation with covid than flu. - not making any statement about absolute CFR/IFR.

No, because you don’t know what the infection rate is by each demographic. You have to compare just the case fatality rate. Comparing fatality ratios alone is too likely to measure unrelated factors.

Fair enough, but would there be a reason it would be different? And even if it were, is that actually relevant?

Anyway, here's some IFR estimations for covid by Imperial college: https://www.thelancet.com/journals/laninf/article/PIIS1473-3...

You see significantly higher multipliers by age group than for flu. As one example, they are guessing teenagers have 1/17th the mortality rate of say a 40 year old. For flu (going by deaths), it's about 1/5th.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#115

Post by Mikeb85 »

wbronitsky wrote: post #87
Mikeb85 wrote: post #47

Earlier quoted context omitted.

> Are you of the opinion that this is simply just a slightly worse flu? I mean I'm about 95% sure I already had it. Had literally every single symptom but the local health authority (Alberta, Canada) wouldn't test me. My SO had it worse but again, they wouldn't test her. Felt like a worse flu + more coughing and shortness of breath. Worse fever. My symptoms were bad for about 3 days, then felt like a cold for about a…

This is the terrible take that will be everywhere in the next few weeks; “I think I had it, therefore I am an expert on the spread of this disease”. There is no data or coherent argumentation here. I’m sorry you were sick, but this isn’t an argument based on facts, it’s an anecdote based off of little that might put people in danger. We need to inoculate ourselves from this argument because we are about to see it eve…

Come on, all the data is out there. There's been 2 million confirmed cases. Pretty much every expert agrees theres far more undiagnosed cases. We know the testing rates. We know who's being tested. The information is out there.

Our local health authority is literally giving away PPE...

Seems your only argument is that the idea it's not as dangerous as initially assumed "might put people in danger".

Except the fallout definitely will. Shutting down the economy, limiting health care access has real consequences.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#116

Post by edmundsauto »

richardw wrote: post #24
blakesterz wrote: post #6

>> The majority of the positive cases so far are among sailors who are asymptomatic, officials say. I don't know much about this kind of thing, but isn't the most important word in that sentence "sailors"? I would think people living on an aircraft carrier are, on average, way different in many major ways than the average American. So it seems like making any kinds of assumptions based on this wouldn't be super relia…

It probably means this is your best possible case outside of an Olympic village.

If it's true that men are more susceptible to infection/complications/death, the only way the population could be better would be if the ship were staffed entirely by women. That would be an interesting scenario for military leadership to plan.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#117

Post by standardUser »

bhouston wrote: post #104
ImaCake wrote: post #101

Earlier quoted context omitted.

I feel that the asymptomatic thing is more wishful thinking in places where infection control has failed. Other countries have shown that you can contain the spread of Covid19, even if there are asymptomatic (or more realistic, low symptom severity) cases.

We need widespread antigen testing in a place like Italy or NYC or Sweden. Would be so informative.

Germany and Finland are doing this. Here are some results already completed in a German town showing that 14% of people tested positive for antibodies...

https://spectator.us/covid-antibody-test-german-town-shows-1...

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#118

Post by three_seagrass »

eximius wrote: post #69
estebank wrote: post #23

Earlier quoted context omitted.

Being asymptomatic is not the same as being immune. It means that more people will feel fine and spread the virus more because they don't know they have it.

It's not clear to me that asymtomatic doesn't mean immune. If the primary symptoms are due to over-replication of the virus and not fighting it enough resulting in cell death in lungs and other airways, then asymptomatic infection indicates the immune system is fighting it enough to fend it off. Now, this rests on symptoms being directly caused by higher virus cell counts rather than toxic byproduct cascades of some…

This is devolving into semantics. Being a asymptomatic means you are infected, which means you are not immune. You can still develop symptoms later and/or still transmit the disease.

You would be considered immune if your body produced antibodies that prevented infection. This immunity can be gained by successfully fighting the infection or by receiving a vaccination that triggers an immune response.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#119

Post by [deleted] »

koyote wrote: post #91
kian wrote: post #55

Earlier quoted context omitted.

Only if they form antibodies. Studies have been suggesting that people who get it in asymptomatic form are not all forming antibodies - leaving them wide open to be future communicators of the disease.

Wouldn't that mean that a vaccine is close to impossible? My layman understanding is that a vaccine relies on the body creating antibodies.

[deleted]

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#120

Post by wbronitsky »

Mikeb85 wrote: post #115
wbronitsky wrote: post #87

Earlier quoted context omitted.

This is the terrible take that will be everywhere in the next few weeks; “I think I had it, therefore I am an expert on the spread of this disease”. There is no data or coherent argumentation here. I’m sorry you were sick, but this isn’t an argument based on facts, it’s an anecdote based off of little that might put people in danger. We need to inoculate ourselves from this argument because we are about to see it eve…

Come on, all the data is out there. There's been 2 million confirmed cases. Pretty much every expert agrees theres far more undiagnosed cases. We know the testing rates. We know who's being tested. The information is out there. Our local health authority is literally giving away PPE... Seems your only argument is that the idea it's not as dangerous as initially assumed "might put people in danger". Except the fallout…

I’m not asserting anything other than that this argument is not based on data.

The data aren’t there, you aren’t an expert, and this argument doesn’t help anyone. That’s the most positive read I can give what I consider to be a reckless take, and this take will be EVERYWHERE in the next few weeks. We need to guard ourselves because this take is deceptive; it lets us feel superior to everyone who is freaking out, which will help individuals calm down at the expense of public health.

Post reply on HN