Understanding that all analogies are flawed, from an imunilogical perspective, vaccinations act like control rods in a nuclear reactor. Without control rods, the chain reaction runs out of control and you get a meltdown or pandemic in our case. As more control rods are inserted, the slower the chain reaction. As more people are vaccinated the less the disease spreads. In each case, the goal is to get the reaction or spread down to the point that either the reactor can dissipate the heat or the hospitals can cope with the new cases. Most vaccines are not 100% effective. That's not the goal. The goal is to get
R as far below 1 as possible. For this to happen, as many people as possible must be vaccinated with whatever vaccine is availabe, be it 98% effective or 58% effective and everyone must continue other prevention measures.
For this reason I see proof of vaccination, masks, hand sanitizer, etc. being required for future Amtrak travel, just as yellow fever vaccination is required to travel to some countries.
P.S. and don't throw out nonsense statements like "It has a 98% survival rate." In the US Army being hit by a IED has a high "survival rate" too. Just how much do you want to spend the rest of your life missing major body parts? Sometimes "surviving" COVID is like surviving a run-in with a landmine.