There is no reason to believe that this actually worked. There were lots of vaccine candidates in early 2020, and many of them failed to produce a strong enough

There is no reason to believe that this actually worked. There were lots of vaccine candidates in early 2020, and many of them failed to produce a strong enough immune responce. This even happened to big corporations like Sanofi-GSK. The hard part is not to produce some vaccine candidates, but to test the safety and efficacy.