Strep throat is caused by the streptococcus bacteria. This bacteria can be picked up from surfaces and hand to hand contact and so on. You could have gotten it from kissing someone with a strep infection or by being very close to someone when they coughed, or touching a surface that someone with strep had touched for coughed on etc. and then brought your hands near your mouth and transferred the bacteria; putting down your PV on a surface that could have bacteria on it - which is anywhere unless the surface is sterile - could also have gotten the bacteria from a surface or another person and you. Sharing a PV with someone else without changing the drip tip could have exposed you to strep (possible you could have bought an accessory someone else had put near their mouth but that's a long shot and the strep usually does not last that long).
Vaping, like smoking does have you doing an activity that brings your hands near/to your mouth/nose and can aid in exposing you to bacteria picked up on hands/objects. So while vaping (like smoking or any hand to mouth activity/habit) "can" cause this the act of vaping itself is not going to give you strep throat.
Now that you have strep throat you don't want to re-infect yourself or give it to others. Good hand washing especially anytime you touch your mouth (so wash your hand when done vaping). Keeping surfaces around your home and work wiped down with a anti-bacteria cleaner - especially places you are a lot or others are like table tops, counters, desks, keyboards, mice or other pointing device, your cell pone and so one, as well as all your vaping supplies. Make sure you are rinsing drip tips under hot water after use, not blowing vapor in someone else's face (the bacteria is transferred on water droplets) especially kids if you have them. Once you have been on antibiotics for a few days and no longer contagious clean your clearo/cartomizers if you can or if disposable toss them and start out with new/clean ones. Of course, its should go without saying not to let anyone use your vaping stuff - you should never share but if you have to wait until you are over the strep before asking if they want to try it.
But no, the act of vaping, strictly speaking, did not give you strep throat.