On 08/01/2022 at approximately 01:45 PM, RN administered MMRV (Measles, Mumps, Rubella and Varicella) vaccine in error to pt. in left upper arm subcutaneously in the child clinic room. Pt. was scheduled to receive five vaccines today which included pediatric Hepatitis A (Hep A), Pneumococcal conjugate (PVC-13), Haemophilus Influenza type B (Hib), Measles, mumps, rubella (MMR), and Varicella (VAR-Varivax). RN misread the vaccination label when pulling MMR out of the freezer. RN believed at the time of pulling the vaccine, that MMR is in the freezer with VAR. The vaccine in the freezer was actually measles, mumps, rubella and varicella (MMRV-Proquad) Both MMRV and VAR were labeled as state vaccines. Which at the time, I believed the patient to be eligible. RN did not complete one of my six rights of administration by double checking the vial on the vaccine to make sure it was the right medication. I believe if I had completely turned the vaccine vial, I would have read the entire label.    RN made a telephone call to parent at approximately 03:10 PM to notify her that her son received a double dose of the VAR which is a live vaccine, I relayed side effects of vaccines and what to watch out such as increase in fever, redness, soreness and pain at injection site and irritability. Parent asked RN "is my son going to come down with chicken pox later and possibly give it to my other son?", and RN replied, "he is not likely to come down with chicken pox and become contagious"   Parent had no further question and she was given my name and the name of my immediate supervisor to call if she had additional questions. Parent did not notice any adverse effects of vaccine at this time but stated to the effect "I will keep an eye on him"   At 05:02 RN made call to Merck, the vaccine manufacturer to get additional information on other adverse effects. RN spoke with Merck. Rep relayed that Merck showed no other adverse effects than those side effects listed for each vaccine as Fever, Irritability, redness, soreness or pain at the injection site, and that contracting chicken pox was not listed as an adverse event, side effect when the two vaccines MMRV (Proquad) and Var (Varivax) were given together. Rep at Merck is to provide information via email on findings with RN.   At 05:21 PM, RN made additional call to parent on MERCK findings on adverse events, side effects when taking Proquad and Varivax together and that there were no findings to support that patients contracted chicken pox after vaccination. RN to email copy of findings from Merck to parent once received. RN asked parent how her son was doing now and she replied "he is resting now as he typically does after vaccination, I gave him pediatric Tylenol before resting, but I have not noticed any adverse effects at this time". She thanked me for the information and stated she would call if she had questions.   On 8/2/2022 at 9:20 AM Information was sent to parent at the email provided from parent, she stated to the effect that this was an old work email she had kept and had been using and never changed it.  Parent was given information provided in attachments from Merck.   On 8/2/2022 at 3:46 PM, RN made a call to parent, I received her voice mail and a voice mail message was left by me asking parent is she had received my email with the information and to call if she had any questions, in addition RN asked parent on the well being of her son.   On 8/3/2022 RN's supervisor made follow up telephone call to parent to inquire on well being of her son, There was no answer, a message was left for parent to return call. No call back known to be received and no return messages were left. Result of outcome of adverse event(s) is unknown due to no follow up response from Patient's parent.