Except that's not what he's saying.
Respiratory vaccines for flu and Covid, etc, function the same way that vaccines for other stuff work; only, that method is much less effective for those specific types of viruses. Not "useless", as you want to claim - just not nearly as effective.
Next Gen vaccines for these viruses need to target different parts of our immune system, which COULD make them as good as the standard vaccine designs are for measles, etc. But, if RFK Jr shuts down our vaccination programs and grants, we will be delayed 5-10 years in getting them.