It showed promise to be

[Dukul12345]

Is there any difference between these two sentences?

1. It showed promise to be a vaccine for COVID-19.
2. It showed promise as a vaccine for COVID-19

 

[GoesStation]

Sentence 1 is incorrect.

Did you write these sentences? If not, please tell us where you found them.

 

[Charlie Bernstein]

You can also say "It promised to be . . . ." It means the same thing as #2 and is more concise.

 

[Dukul12345]

Sentence 1 is incorrect.

Did you write these sentences? If not, please tell us where you found them.

When I saw this phrase "show promise" I tried to make these sentences but wasn't sure enough whether these are correct or not. Could you please explain me why it is incorrect?