Topic: Recent research on immunity and spread

[steveh]

New York Magazine has a good summary of the current understanding of virus spread:

- People who have had it already are now having some effect on lowering the spread in places where infection rates have been higher and this may help in any winter wave.

- For effective herd immunity you may not need an infection rate as high as 60% and it could be as low as 20%, although there are competing views on this. How much is immunity, how much is measures like social distancing and mask wearing and how much is issues related to the local population is a long way to being established.

- If this rate is lower then a vaccine will not need such a high rate of adoption and the vaccine will not need to be so effective - which may be likely with earlier ones.

- Having had other coronaviruses recently probably won't affect you getting Covid-19 but may have some impact on the severity of it. Some researchers say this may be one factor in younger people getting it less severely as they are more likely to have spent time in places with lots of others where common colds spread but others dismiss that it has a significant effect, with age and genetics having far more impact on outcome.

- The disease is getting less severe. Some is due to better treatment, some to better protecting the elderly and with spread becoming mainly among the young. Possibly some is due to "mortality displacement" where the most vulnerable die first and the population left are those who have better protection.

Worth reading in full rather than my quick summary: https://nymag.com/intelligencer/2020/08/reasons-for-covid-19-optimism-on-t-cells-and-herd-immunity.html

[Chedney Honks]

Very interesting and promising stuff, cheers. It's genuinely heartwarming to think that we may well be through the worst of it in certain parts of the world.

I have to say though that I still hope it does get really bad or I will look like a right plum!

[QDRPHNC]

Thanks for posting that.

[BlodwynPig]

Surely irresponsible to publish that? Means more risk takers taking this as gospel. It is not gospel at all.

[frajer]

Wouldn't say it's irresponsible. Risk takers are already taking risks. To be honest it was refreshing to read something with even 5% optimism for the future.

[steveh]

I think the article does a good job in showing where the uncertainty lies and the differing views of researchers. There's a lot of wild claims about herd immunity out there from people who don't have the background on the subject and this helps rein them in.

[Cloud]

I don't believe anything on the internet any more, but it's nice to see some optimism at least!

[George Oscar Bluth II]

On the herd immunity thing: it is once again worth watching Sweden, whose numbers have started to drop and yer man Tegnell, the architect of their herd immunity strategy,[1] thinks that possibly they are reaching some form of herd immunity. It's nice to Sweden to play the control group for the rest of us isn't it.

1.	Which, to be clear, I wholeheartedly opposed at the time and continue to do so given how little we know about the virus etc etc

[Shoulders?-Stomach!]

For example, it looks as if the low German fatality rate is not due to their superior testing capacity, but rather to the fact that the average German is less likely to get infected and die than the average Brit. Why? There are various possible explanations, but one that looks increasingly likely is that Germany has more immunological “dark matter” — people who are impervious to infection, perhaps because they are geographically isolated or have some kind of natural resistance. This is like dark matter in the universe: We can’t see it, but we know it must be there to account for what we can see

Fucking hell

[bgmnts]

That doesn't sound a very scientific approach.

[H-O-W-L]

Surely irresponsible to publish that? Means more risk takers taking this as gospel. It is not gospel at all.

Blodders you're normally on the button with this stuff but this is the worst take. You want to be less informed because some people would twist the information to justify a worldview they're already taking w/o justification? Huh?

[George Oscar Bluth II]

Fucking hell

Immunologists: I dunno mate, we're basically making stuff up now. Could it be because of those superior Aryan genes?

[idunnosomename]

Maybe Germans are made of dark matter

[frajer]

Black Forest Matter?

[Cloud]

ALL forest matters.

[JamesTC]

All forest gateau.

[Jim_MacLaine]

They're all Forest Gateau by the time I've finished with them.

[frajer]

Loved him in The Shield.

[steveh]

MIT Technology Review has a piece on population immunity which includes this, which I hadn't considered before:

Natural infection also turns out to be extremely efficient at reducing virus transmission—even more effective than an equal number of people getting a vaccine. The reason is that the virus has been finding and infecting precisely those people who—whether because of behavior, circumstances, or biology—are most likely to be part of transmission chains.

Perhaps they are college students on spring break, or hospital nurses, or people who touch their face all the time. Whatever the reason, once these individuals become infected and are removed from the equation through death or immunity, the effect on the pandemic is outsized. By contrast, vaccinating a sheltered older person might protect that individual but does relatively less to stop transmission.

https://www.technologyreview.com/2020/08/11/1006366/immunity-slowing-down-coronavirus-parts-us/

Also points out that we still don't know how long immunity will last. For example, if people in London got it mostly in March / April then it's possible those who were asymptomatic or had milder cases may no longer be immune this winter and become spreaders again.

[JamesTC]

I remember super-spreaders being a big thing mentioned in April/May but not seen it mentioned too much recently.

I think in terms of the vaccine it might be good policy to target early vaccination supply on people likely to be in occupations that tend to super-spreading such as health care, retail and hairdressing.

[MrMrs]

Following

[Shoulders?-Stomach!]

https://www.forbes.com/sites/mishagajewski/2020/08/11/stop-trying-to-make-herd-immunity-happen-swedens-attempt-at-covid-19-herd-immunity-failed

This article starts off with the usual clickbait angle before actually providing information which includes the article above. In short 'it is all not that simple', but try stopping news media from begging for clicks.

[dissolute ocelot]

Natural infection also turns out to be extremely efficient at reducing virus transmission—even more effective than an equal number of people getting a vaccine. The reason is that the virus has been finding and infecting precisely those people who—whether because of behavior, circumstances, or biology—are most likely to be part of transmission chains.

Regardless of any lasting immunity, people who've had it once may not be so stupid as to get it again. Obviously not everybody who gets it was stupid, but if people who've had it change their behavior even a little bit, that will have an effect.

[Endicott]

Nurses stop going to work, for example.

Hairdressers all commit suicide.

Telephone sanitisers get on a space ship.

etc

[Cloud]

I was just thinking earlier how the telephone sanitisers kind of got an unfair treatment in all that, in hindsight

[steveh]

This is a good overview on the immune system, how it responds to SARS-CoV-2 and what is known so far about longer immunity: https://www.theatlantic.com/health/archive/2020/08/covid-19-immunity-is-the-pandemics-central-mystery/614956/.

[FredNurke]

I was just thinking earlier how the telephone sanitisers kind of got an unfair treatment in all that, in hindsight

Well, there's the little detail about how the Golgafrinchan civilisation ends up being wiped out on their home planet.

[steveh]

Some research tracking people who had had Covid suggests immunity may not be short lived:

Covid-19 patients who recovered from the disease still have robust immunity from the coronavirus eight months after infection, according to a new study. The result is an encouraging sign that the authors interpret to mean immunity to the virus probably lasts for many years, and it should alleviate fears that the covid-19 vaccine would require repeated booster shots to protect against the disease and finally get the pandemic under control.

The study, published January 6 in Science, contrasts with earlier findings that suggested covid-19 immunity could be short-lived, putting millions who’ve already recovered at risk of reinfection. That predicament wouldn’t have been a total surprise, since infection by other coronaviruses generates antibodies that fade fairly quickly. But the new study suggests reinfection should only be a problem for a very small percentage of people who’ve developed immunity—whether through an initial infection or by vaccination.

https://www.technologyreview.com/2021/01/06/1015822/covid-19-immunity-likely-lasts-for-years/
https://science.sciencemag.org/content/early/2021/01/06/science.abf4063

On the downside, people who have had it continue to have issues for a long time:

At 6 months after symptom onset, fatigue or muscle weakness and sleep difficulties were the main symptoms of patients who had recovered from COVID-19. Risk of anxiety or depression as an important psychological complication and impaired pulmonary diffusion capacities were higher in patients with more severe illness. These results support that those with severe disease need post-discharge care. Longer follow-up studies in a larger population are necessary to understand the full spectrum of health consequences from COVID-19.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32656-8/fulltext

Nine months on and while other symptoms have gone, my lungs are still not quite back to what they were before. With original SARS it took some people up to ten years to get full lung function again.

[Poirots BigGarlickyCorpse]

I'd rather have the vaccine than develop immunity through actually getting the disease and risk being fucked up for months and months, thank you.

[greencalx]

Edit sorry outdated.