No volunteer will risk that because the vaccine might not work. Phase 2 is just to show there's good immune response in humans.
The phase 2 trial mentioned is for a specific antigen, thus it is even more likely to fail when compared to a live kill or attenuated vaccine.
I disagree. There will be volunteers who want to be deliberately infected.
Remember, the death rate is almost ZERO for under 40s.
And if 50% of the population is going to be infected anyway, why not get the vaccine, and then have an even better chance of surviving.
Doctors and nurses (who have had the vaccine) would want to be deliberately infected as well.
Better to receive a small COVID-19 dose now, which will confer immunity.
The alternative is to be exposed to large amounts of virus in a hospital, which could potentially overwhelm the immune system.
The indications from other viruses are that the amount of exposure can matter a lot.
But we'll have to TEST this with deliberate infections
Article on intentional infection study below.