When we use Biga in bread or pizza doughs, we should add a small quantity of fresh yeast.
In fact, if you use a traditional biga fermented for 16/18 hours, I recommend adding 0.2% of fresh yeast to the weight of flour used in the final dough.
For example, if you want to use 1kg of flour to make bread (or pizza) with 20% of Biga, then you need to consider:
The flour needed to make the Biga will be: 20% of 1kg= 200gr
In the final dough, I will use the flour left after the Biga: (1kg of flour - 200gr used for the Biga)= 800gr
On this quantity, the quantity of fresh yeast to add to the recipe (in addition to the one already used for the Biga) will be 0.2% of 800gr= 0.2gr (it would be 0.16, but for such small recipes, you can round up)
Even if you want to prepare a 100% recipe, I recommend adding a small amount of yeast during the final dough.