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Comment by ralmeida | Hacker News Reader

Comparable individual outcome, worse societal outcome - you still spread it, so no reduction in overall cases, unlike a vaccine.

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I encourage everyone eligible to get vaccinated if they can, but it does little to prevent spread. Over the long run we'll all be exposed no matter what we do. The real benefit of vaccines is in reducing the risk of severe symptoms.

https://www.nature.com/articles/d41586-021-02689-y

https://www.businessinsider.com/delta-variant-made-herd-immu...

I don't think either of those sources justifies "does little to prevent spread." The language used in them is considerably more hedged, eg:

"But growing evidence suggests that, with the Delta variant, fully vaccinated people can still transmit the virus."

And this:

"Unfortunately, the vaccine’s beneficial effect on Delta transmission waned to almost negligible levels over time. In people infected 2 weeks after receiving the vaccine developed by the University of Oxford and AstraZeneca, both in the UK, the chance that an unvaccinated close contact would test positive was 57%, but 3 months later, that chance rose to 67%. The latter figure is on par with the likelihood that an unvaccinated person will spread the virus."

Is also not super relevant— what most people want to know is not whether a breakthrough infection is capable of spreading it, but whether you're more likely to get a breakthrough infection. I think most vaccinated people (which is most people in rich countries now) care much more about the unvaccinated -> vaccinated transmission and the vaccinated -> vaccinated transmission than they do about vaccinated -> unvaccinated.

> ...but it does little to prevent spread.

Actually it does reduce transmission

https://www.nbcnews.com/health/health-news/vaccinated-people...

Vaccination slightly reduces the risk of transmission for individual interactions (at least for a while) but that just stretches the curve out a little. Since SARS-CoV-2 is now endemic throughout the worldwide human population (plus several other mammal species) we can all expect to be exposed multiple times throughout our lives no matter what we do. Fortunately the vaccines are very effective at preventing deaths.

https://www.thelancet.com/journals/laninf/article/PIIS1473-3...

> Vaccination slightly reduces the risk of transmission for individual interactions (at least for a while) but that just stretches the curve out a little...

That's a disingenuous statement though because vaccines also help prevent getting infected in the first place, which reduces transmission. This study seems to focus on vaccinated people who had a breakthrough infection. If you read the 'Interpretation' section:

> Vaccination reduces the risk of delta variant infection and accelerates viral clearance. Nonetheless, fully vaccinated individuals with breakthrough infections have peak viral load similar to unvaccinated cases and can efficiently transmit infection in household settings, including to fully vaccinated contacts.

The first sentence implies vaccination reduces the risk of getting infection. The second sentence is talking about vaccinated people with a breakthrough infection having similar viral load. Therefore saying "Vaccination slightly reduces the risk of transmission for individual interactions" is untrue because it ignores the infection prevention mechanism of the vaccine. It's a lot better than 'slightly'

> it does little to prevent spread

How much, exactly?

> Over the long run we'll all be exposed no matter what we do

Plausible, but your sources don't appear to support that, other than the claim from Mr. Pollard. Is there anything I'm missing?

“The most statistically significant data point is that vaccinated people certainly have a faster rate of viral decline,” said Ferguson, “so they may potentially be infectious for less time, but they don’t necessarily have any reduced peak of viral load. Most transmission probably happens around that peak of viral load, which is why we think we’re still seeing substantial transmission rates from vaccinated people, both to unvaccinated people and to other vaccinated people.”

https://www.bmj.com/content/375/bmj.n2638

And yet your own linked study says, right in the first paragraph, that vaccinated contacts got it 38% less often.

Is it possible that this is not enough, and “virtually everyone will eventually be exposed”? Yes. Is it possible that COVID will become endemic and many (but not all or even most) people will be exposed? Yes. Have I seen any source that makes a strong case for this? Not yet.

I thought the latest research was that the vaccinated can still spread COVID?

Some might, but not all, which is still a reduction

Vaccine doesn't prevent spreading.

No: https://www.nbcnews.com/health/health-news/vaccinated-people...

Citation needed - and note I didn't say it prevents "100% of spreading"

Yet, with the COVID vaccine, you still spread it, too:

https://theexpose.uk/wp-content/uploads/2021/09/Pierpont-Why...

https://www.cdc.gov/mmwr/volumes/70/wr/pdfs/mm7031e2-H.pdf

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3897733

So, how could the outcome at the societal level be worse?

While a vaccine is not 100% effective in preventing the spread of new cases it is at least somewhat effective.

Do you have a source for R0 being _absolutely equal_ in vaccinated vs unvaccinated?

Give them time.

Time can also yield better vaccines, a policy of recurring vaccine doses (like the yearly flu shots), and milder variants that can emerge and become dominant, like some believe is what happened with the Spanish Flu.

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