Here's an old recipe, but it is considered unsafe by today's standards since it is not pasteurized in a canner and cherry tomatoes were taken off the approved canning list because it was learned their skin density prevented heat penetration and proper killing of bacteria spores.
Pickled Cherry Tomatoes
2 cups water
2 cups white vinegar
1 Tsp salt
1 TBsp sugar
Bring to the boil.
In the meantime put 2 peppercorns and 1 clove of garlic (peeled) in clean, sterilised jars. Fill with cherry tomatoes (prick them so that they can absorb pickling liquid). Pour hot vinegar mixture into jars. Seal. Wait 4-6 weeks before eating.
I'm sure you could vary the amount of spices (more salt, less sugar), and/or add different spices. You could also add some herbs to the jars. You could probably vary the vinegar/water ratio, too. More vinegar, if desired.
Support bacteria. It's the only culture some people have.