Spring/summer Pruning for Pears

I have about 20 pear trees that didn't get fully pruned in the dormant season that are in 6th leaf: Warren, Magness, and Comice. Terence says I should go ahead and prune them now with impunity, but I am a bit reluctant, especially to make any heading cuts because of disease pressure. So far we have no fire blight this year (knock on pear wood

Fruitilicious Farm
Zone 9b in California