Incident occurred on 9/26/2020 at the drive thru flu shot clinic.  As soon as my son received his flu shot, he wasn?t responding to me when I asked him how he felt. His eyes started rolling back and soon after he raised both of his arms and started shaking and twitching backward and fell to the ground inside the car. Based on my observation, I knew my son passed out so I immediately jumped out of the passenger?s seat and rushed to his side and called the LVN for help. The LVN came by and saw my son on the ground. She doesn?t seem to know what to do. Another LVN came over then they both put ice packs one he back of my son?s neck. I mentioned to call 911 but they didn?t respond to me. The second LVN who came by stated that my son needs to be taken inside the nurse station. My son was awake after few minutes but looked extremely pale with white bluish lips. I have a video of him during the shot and his lips did not look anything like that. Anyhow, once my son was in the nurse station, the nurse checked his vitals and I was told that my son is fine and was told that we can go home. I asked the nurse to see if my son can be assessed by a medical doctor but I was informed that there is no MD on-site on Saturday and I can do whatever I want either to take him to ER or urgent.  She said it?s up to me on what I want to do with my son.  The impression that I got from the nurse was there is nothing that she can do. I told the nurse if there is no MD on site then my son needs to be transported to ER or urgent care for assessment since that was the very first time that he had a reaction after receiving a vaccine. Nothing like that ever happened to him before. I informed the nurse maybe we should call 911 because I do not safe to take my son to ER by myself. I wasn?t sure if he had a seizure like symptoms or he had an allergic reaction to the vaccine. Since no one was able to assess my son I demanded the nurse to either call 911 or find out what the protocol is from Doctor's office even though she just doesn?t seem like she wants to call the ambulance for us. Anyhow she came back 5-10 minutes later and told me that she just called 911 and she specifically mentioned to me that was the protocol. I just don?t understand why she didn?t call the ambulance in the very beginning??? After my son arrived in the ER, the doctor order EKG, chest x-ray and checked my son?s blood sugar. Everything came back normal. The prognosis was vasovagal however she said there may be a slight chance of a seizure due to the twitching and shaking symptom that my son had. She referred my son to see a neurologist. The ER doctor did mentioned to me that the nurse at the drive thru clinic should have immediately call 911 when my son passed out. I did spoke with my son?s PCP within Doctor's office the following Monday and I was told that all kids should receive their shots inside a clinic instead of getting the shot inside a vehicle in case of any medical emergency . I told her there was no sign and the LVN who administered the shot never inform us about the possible side effects/risks of the flu shot for children. Then on Wednesday, the neurologist contacted me over the phone and told me the drive thru clinic should have a MD on site. I explained to him what happened so he ordered an EEG for my son. EEG was not done until about 2 weeks after the incident but the result came back normal. Based on the result of all the testings came back to be normal, I don?t know if there is a way for me to find out if my son did in fact had an allergic reaction to the flu vaccine itself. I just felt that the incident should not have happened to a healthy kid. Due to what happened, I am very concern whether or not my so son should be getting the flu vaccine next year. I did filed a case with Doctor's office but I have not received any official response as of today. The incident occurred 7 weeks ago.