So what? That's a total non sequitur. The measles vaccine is highly effective at preventing infection and transmission. That situation doesn't obtain with SARS-CoV-2. The vaccines are pretty good at preventing deaths but they have only a marginal and temporary effect on preventing infection and transmission. For the foreseeable future, every time you interact with another person (or certain other mammal species) there is a significant risk they will transmit the virus to you. That is our reality and wishful thinking won't change it.

Instead of trying to avoid infection and most likely failing, a more productive approach is to focus on reducing the risks of a bad outcome when you inevitably do get infected. For most people that means getting vaccinated plus resolving any major risk factor conditions such as obesity, type-2 diabetes, and hypovitaminosis D.

And you didn't answer the question. Which specific "experts" claim it will be possible to avoid infection?