For how long after Vivace are the "wounds" still open/healing?

Vivace RF microneedling creates tiny microscopic holes that are open for about 4 hrs.  It is best not to apply anything at all to the area till well after.  It is ok to do a light peel 2 weeks after.  In our office we recommend a Clear and Brilliant procedure 2 weeks after to improve the epidermis and give the patient optimum results.

Vivace Micro-needling creates micro channels in your skin that will remain open for up to six hours following your treatment. We advice our clients to use a gentle cleanser  followed with a good moisturizer and sunscreen. Then to resume your normal skin care post 72 hours. You can schedule your mask or glycolic peel post 2 weeks. 

Congrats on your first treatment!
A post treatment instruction sheet goes home with every patient who has any treatment in my practice. This is an excerpt out of  my Vivace Microneedling RF post treatment instruction sheet: 
Vivace Treatment opens thousands of micro-channels in the skin which remain open for 6-8 hours. DO NOT APPLY ANY MAKE UP OR ANY UNAPPROVED PRODUCTS ON YOUR SKIN DURING THE FIRST EIGHT HOURS. Serious infection, downtime and scarring may occur otherwise.
Also included are the approved products during the first six hours as well as bespoke customized skincare regimen to achieve skin transformations. 
So rest assured that the micro treatment channels are already closed. But as far as what you should use on your skin, I recommend a customized skincare program under the guidance of an expert physician. 
Best of luck in your ageless beauty journey, 
Dr. Monica Bonakdar