I have a 22 month old boy and I would guess that he'd be far more likely to seriously injure/kill himself with a knife than a gun. He's rather clumsy and would probably be 10 times more likely to fall and stab himself with a knife then shooting himself or someone else.
Now iirc the story from Kentucky involved a 5 year old accidently shooting his 2 year old sister with a .22 he for his birthday? I also have a 6 year old to go along with the 22 month old. She isn't interested in guns and has never fired one. They scare her and that's fine I would never force it on her. I do, however have guns in the house (they're all in safes that neither child has access to but still in the house nonetheless) and have taught her basic gun safety for that reason. She knows to assume any gun she comes in contact with is loaded. She knows to always know where the barrel of any gun is pointed and to never point a gun (loaded or not) at another person. She also knows that under no circumstances should a gun ever be touched (her or a friend) without an adult being present. As opposed to trading a gun for a knife, I'm guessing the parents of the dead 2 year old are wishing they would have done the same. Her brother broke all 3 of those rules. If he had followed just one, that whole situation would have been avoided.
Also (according to the CDC) Drowning is leading cause of unintentional death among children 1-4. Then motor vehicle accident, fire, suffocation, accidental poisoning, ect... Accidental shooting wasn't even in the top 10. So I assume that people with children in that age group who have pools, cars, fireplaces, and Drano should trade them for a gun. Their children would be safer if they did.