Omicron variant more resistant to vaccine but causes less severe Covid: study

In a normal trial, you give half of participants a vaccine, and half of participants a placebo. Then, you wait around and see how many people in each group catch COVID naturally and get sick. Your vaccine works if fewer people who received a vaccine get sick compared to the placebo.

In a challenge trial, you give half of participants a vaccine and half of participants a placebo, and then purposefully expose them all to COVID so you don’t have to wait around for them to catch the virus naturally. As before, your vaccine works if fewer people who received a vaccine get sick.

A challenge trial gives you data which is more, not less, robust, because you’re controlling for more variables between groups. And we’ve used challenge trials to test vaccines in the past—just, never with a disease that’s nearly as deadly as COVID.

Any firestorm would result from a trial participant dying from the COVID they were purposefully given (which could absolutely happen), not from the vaccine. This has nothing to do with vaccine mandates.

The thing is, before the COVID-19, the world had barely heard of mRNA vaccines and suddenly there are billions of people vaccinated across the world in 2 years. I have no intention of denying that these vaccines have saved millions, if not billions of lives by preventing hospitalization, death and further overloading of medical systems worldwide.

But still, a skeptic part of my brain can't seem to 100% accept the fact, even though it might be a medical miracle. It's that scratch on your back you can barely not reach, and it stays itchy for days and months.

On the other hand, vaccines that use inactivated or dead viruses to incite an immune response has been known for more than two centuries, whereas this feels... different.

Unfortunately, at the time of writing this, none of the other answers to this question in this thread have been proper responses that directly answer the question, except the one about "changing priorities from do no harm to optimize for least harm" that seems to make most sense.

So, I'd love to have a direct answer, no analogies, no "imagine how worse it could have been without vaccines", no "disease X kills more people than Covid and mortality for mRNA vaccine for Covid is negligible compared to that", no shifting goalposts, no guilt-tripping for being skeptic, just a straight, direct answer to this question of the OP.

The medicine is not yet sufficiently shown to be safe and effective.

Epidemiologists do frequently use exponential growth in discussions of theoretical spreading, but they are not correct. It does not fucking matter. They’re just wrong. Is the long term spread of a disease exponential. No. We can say this with 100% confidence. Why? Because they do not increase exponentially over time. They QUICKLY hit ceilings and inflection points.

This is the problem. If you call a system exponential because it looks like that at the beginning, your estimates of the middle and end will be hugely off. Massively wrong.

It is obviously apparent looking at Covid that it does not spread exponentially. The impact of this understanding is enormous. In an exponential model, a virus that is twice as infectious could be expected to infect 4x as many people over the same period. If the model is logarithmic, twice as infectious will likely result in LESS THAN TWICE the number of people infected.

Scary predictions that a small increase in spreading will exponentially increase the number of infected people do not hold up against observed real world data. We should be cheering on a more spreadable but less deadly disease. Scale matters, of course, but we aren’t seeing anything like that.

If you want to come back to this in one year and check to see if omicron infected even twice the number of people that delta did over the same time period that’s a bet I’d surely take.

People think exponential is an accelerating rocket ship to 100% infected. It is not. It’s a decelerating trend likely to stall out well below 100%.

If the R factor increases from 1 to 2, over a LONG period, you would be wrong to expect exponentially more cases. You would probably see fewer than 2x the cases. You would see it expand much, much faster initially.

But both would see slow downs at similar inflection points.

The very first sentence of your own linked abstract:

> The INITIAL exponential growth rate of an epidemic is an important measure of the severeness of the epidemic, and is also closely related to the basic reproduction number. Estimating the growth rate from the epidemic curve can be a challenge, because of its DECAYS with time.

the long term model is not exponential. This really should be obvious, but you cannot create an accurate disease model that does not show the impact of population size. Pure exponential models are only relevant on a theoretical infinitely large population that is well and randomly mixed. When you establish that there’s only so many people, the growth rate has to decline, and not at 100% of the population. It stalls out well before that. Look into random graph models.