Coronavirus: 8% of recovered patients in one study didn't develop antibodies | Hacker News Reader

Coronavirus: 8% of recovered patients in one study didn't develop antibodies

businessinsider.com

29 pointspseudolus11 comments

Sensationalist headline.

1. Sample size was 130

2. Hasn't been peer-reviewed

3. "What this will mean to herd immunity will require more data from other parts of the world," Huang Jinghe, the leader of the research team behind the report.

Only interesting part: Interestingly, the levels of antibodies patients produced seemed to correlate with their ages: Middle-aged and elderly recovered patients had higher levels of antibodies. Nine of the 10 of the patients who did not develop detectable levels of coronavirus antibodies were 40 years old or younger.

> Nine of the 10 of the patients who did not develop detectable levels of coronavirus antibodies were 40 years old or younger.

So, a small number of the people who are most likely to have asymptomatic, mild or sub-clinical bouts of CV19 don't immediately develop immunity or measurable resistance on their first exposure. This finding (if confirmed) won't have a significant impact on hospital surges or fatalities.

The other thing to remember is that the same effect is seen in vaccines and other viruses. Nothing is ever 100% because humans are different. Also, serological tests for antibodies aren't perfect either. My understanding is the very best reach 95% accuracy.

This is also the same group of people governments seem to be relying on to provide herd immunity - so it could still be a major issue

It's an indication of mild disease if your body can fight it using generic white blood cells rather than specialized antibodies.

Yes - but if we're concerned about people who are asymptomatic transmitting, and we need herd immunity in order to prevent transmission in general to the most vulnerable, then you 'getting it' and then getting better without producing antibodies means you can get it again, and thus still act as a transmission vector.

Possible explanations:

* Maybe those patients never had coronavirus in the first place? Just because there is some viral DNA in your nose doesn't mean you're infected - you might have just breathed in some infected air and the mucus up there is doing its job of getting it out.

* Many different antibodies might be involved in fighting an infection. Perhaps there are other as-yet unidentified antibodies?

The only suprising thing here is that some journalist seem to assume these tests are 100% acurrate. Assume they are less than 100% accurate and many of these kind of headlines can be dismissed.

It has impact for antiserum blood plasma transfusion, where you take blood from a recovered Covid19 patient and give to one with a severe case. If 8% does not have anti bodies you may need to get blood plasma from several donors to hedge the statistical odds of 8% do not develop anti bodies. Say you get blood plasma from three donators is that 0.08 times 0.08 times 0.08? At least it would be safer with two middle aged donors.

For perspective: At a New Jersey hospital "Of more than 3,000 people who have offered to be donors, only 38 have met the initial screening criteria. "

https://www.nytimes.com/2020/04/11/nyregion/coronavirus-anti...

How do they know the antibody test they used finds all of the antibodies that patients develop to fight off COVID-19?

There are many proteins on the surface of any given virus for your immune system to target. This is why vaccines produce weaker immunity than catching the disease would.

Also, what is the baseline false positive / false negative rate of the test? The widely-available antibody tests aren’t particularly good. (They’re mostly useful for random testing and epidemiology, from what I can tell.)

My take is that if a serious disease existed for which you don't develop immunity we'd all be long dead by now.

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