The general guidance hasn't changed. The risk to each other has gone up as Delta spreads, because it's more dangerous. There will probably be other dangerous variants given the huge breeding ground for the virus among the unvaccinated and immune compromised.

Get vaccinated, lower your risk, lower the risk to everyone around you and to the general population of the earth. (And it's incredibly harmless).

It's not absolute protection however. But it greatly reduces the probabilities of propagating the virus.

In a population the effect is multiplied more than the effect on an individual, because of the reduced propagation. If enough are vaccinated that multiplier does make it near-absolute protection.

Thus, it protects you, and it also protects each other through the multiplier effect.

It also greatly reduces the chances of hospitalisation and death from infection if you are one of the unlucky ones who gets Covid-19 anyway in spite of vaccination.

> Now we are getting a different message

No, we aren't.

The message from the authorities has been consistent on why people should be vaccinated, including acknowleging that it isn't absolute protection (with reported probabilities), that people should still take care to protect each other in other ways, and that collective multiplier effects mean it's important for nearly everyone to be vaccinated - people protect each other, not just themselves.

Despite not providing absolute protection to an individual who takes it without others taking it, it is believed to be able to provide nearly absolute protection if vaccine takeup is sufficiently widespread and social behaviour stays careful enough - because R < 1 means the virus dies out instead of continuing to spread, and R depends on collective vaccine takeup and people's behaviour.

Measured likelihoods of infection with the vaccine are reported from time to time, as is the effect of different virus variants. Due to the complex nature of social interactions in different environments, and the fact that data is continuously being produced and analysed, and nothing is static, those reported values are not the same everywhere, and new values keep emerging.

> This is why people develop doubts that the authorities have any real idea what they are talking about.

Different people explain the message in different ways, and emphasise different aspects. It does not mean the authorities are changing their mind on the major points.

But public health messaging is a difficult field of its own: If you spell out all the details and nuances, that some people would like to hear, most people tune out and don't follow the advice no matter how important. They also forget details, then when they hear the same thing put a different way with different emphasis, it sounds different and perhaps contradictory, but isn't really.

It has to be simplified and memorable, for people to follow it, unfortunately.

You're right that when people hear different versions of the same message, it leads people to wonder if what they are hearing is consistent.

I'll try to provide my simplified version:

When you get vaccinated and your grandparents vaccinated and everyone you interact with vaccinated, then wait a while, eventually you will be pretty safe visiting them.

If you only get yourself vaccinated but your grandparents don't, nor any of the people you interact with daily, you will be better protected than them, but they can still give you the virus (with lower probability), and you can still pass the virus on to your grandparents. You'll probably not be too ill because the vaccine protects against severe illness as well, but you might still carry it and pass it on to someone who does gets severely ill. This is why it's so important to have almost everyone vaccinated around you, not just yourself.

Sort of; we don't (and won't) entirely know.

With the delta variant becoming more common, it's seeming like vaccinated people might still be able to transmit the disease, even if they don't become infected themselves. There's also the matter of asymptomatic infection: remember that the 95% efficacy numbers reported by Pfizer and Moderna (for example) are about symptomatic infection; during their clinical trials, they only tested people if they showed symptoms.

And if a vaccinated person is infected but asymptomatic, they may never even know about it. Technically we may or may not call that a "breakthrough infection", but that person could still presumably infect an unvaccinated person, and that's the thing that matters.

> Obviously there may be some individuals who can't get the vaccine, but that should be a relatively rare circumstance, and could have policies around dealing with it.

Right, and having people around them who are unvaccinated by choice is an unnecessary risk to those who can't be vaccinated.

https://www.cdc.gov/mmwr/volumes/70/wr/mm7021e3.htm