It really depends on alot of factors. Gynae wld be the best to answer. My gynae told us best to wait for at least 2 years. But I know of moms who cld do a successful vbac aft 1.5 years. I had csect for my boy but I'd prefer to wait more than tt to ensure tt my wound healed properly. I'm now in my 2nd pregnancy and will be delivering when my firstborn is almost 3 years old. Hoping tt I cld do normal this time since baby is smaller. My first was a big baby at 3.7kg.
If im not mistaken if the gap is short, might need to csec again as contraction might affect the previous wound. Can try search for VBAC