Hacker News Reader

Comment by BiteCode_dev | Hacker News Reader

Do we know how long does the vaccine holds?

Is that like polio and lasts for years, or like the flu and you need a new dose each year?

There isn't really a way to know for certain (as not much time has passed), but there are hints that it might last for years[0].

[0]: https://www.nytimes.com/2020/11/17/health/coronavirus-immuni... (with links to the studies inside)

Unless I missed it, there hasn't been any data released. I'm only seeing PR accouncements.

AIUI, the thing that makes a vaccine's effectiveness very short term, like flu vaccines, is the natural evolution of the virus, not its effect on the immune system. It's not that people who got a 2015 flu aren't still immune to the 2015 flu, it's that wild flu virii look different in specific ways that cause them to slip by. As such, I think these drug companies don't really have much to release for each vaccine.

(That isn't to say the immune system can't forget immunity - TDAP boosters are for evolution, but for refreshing the immune system - but that super short term immunity like flu, AIUI, is about the virus not the vaccine.)

> As such, I think these drug companies don't really have much to release for each vaccine.

They should still release the data. PR releases don't always match reality.

> Unless I missed it, there hasn't been any data released. I'm only seeing PR accouncements.

Because there is no long term data on covid19 mutation speed.

You need a cohort to take the vaccine and then some time before doing a retroactive study.

There's still data, and it hasn't been released. I would like to know the details of 95% effective.

I was listening to an interview with Paul Offit[1] a vaccinologist and member of the FDA Vaccines and Related Biological Products Advisory Committee (which advises on COVID-19 vaccines).

His message was "You honestly don't know ahead of time", but his caveatted guess was actually that it would be long-lasting (giving the example of measles), not like the flu.

[1] https://open.spotify.com/episode/6Z7m56ACJ1VZ0ZKuw4iiGb

I'm in a rush, so hopefully someone can dig up some actual links to scientific papers, but current immunity from naturally infected people has stayed strong and shows no sign of weakening. The immune response from the vaccination has at least as strong, so in all likelihood we're looking at very long response.

Doesn't immunity only last several months though?

No, that's just been a popular conspiracy theory.

No, it stays strong and shows no sign of weakening.

According to several studies, that's not true.

"Two new studies demonstrate how severity of disease is predictive of longer-lasting antibody production and detail how immunity wanes over time but may exist for up to 7 months."

https://www.cidrap.umn.edu/news-perspective/2020/10/studies-...

https://www.cdc.gov/coronavirus/2019-ncov/hcp/duration-isola...

There's also evidence of re-infection

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

You (or rather the writer of that news piece) apparently confused antibodies and immunity. Not only are antibodies not the only mechanism of the adaptive immune system, T cells are harder to test for but equally important. Also it's normal that the body doesn't keep them around indefinitely after an exception. It creates memory cells and quickly recreates antibodies and T cells when needed.

There is evidence that reinfection does occasionally happen, but none that it happens frequently enough to worry about. The paper you've linked mentions four cases.

You're right, but are there any peer reviewed papers that back up your argument?

> The paper you've linked mentions four cases.

Those are confirmed cases. That doesn't mean there's only 4 total.

I don't know if there are any papers for Covid in particular but it's how the immune system works in general. AFAIK there is no reason to assume it Covid differs in that respect.

> Those are confirmed cases. That doesn't mean there's only 4 total.

I'm sure there are more, but how many? There have been hundreds of millions of infections (according to the WHO). If there are a few dozen or even a thousand reinfections among them, it's not a phenomenon we need to worry about.

We could assume that reinfections are common even without any evidence for or against, but then we are playing something akin to Pascal's wager. Also, I think if reinfections were common, by now we would very likely have evidence for that by now.

Your first link only focuses on (the easier to test) antibodies, and doesn't mention T cell memory, which is the much more important factor in long-term immunity.

And of course there are going to be individual cases of reinfections with 55+ million cases.

Your logic checks out, but are there peer reviewed papers that back up your argument? This isn't my field, so I'm not aware of any.

There is one right in the list on the CDC page you linked[0]. There is also a recent Nature paper[1] that shows that T cells levels are stable for at least the first 100 days they observed. I don't know of a specific link to send you for that, but that usually indicates T cell immunity on the timescale of multiple years (otherwise some drop in levels would have already been visible in the observed time period).

[0]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7427556

[1]: https://www.nature.com/articles/s41591-020-01143-2

> The immune response from the vaccination has at least as strong

Is that true? I always thought it was at most as strong (eg, David Katz says so here: https://youtu.be/YLLENema1Co?t=462), but I'm seeing this assertion float around also. Which is it?

Reply on news.ycombinator.com