Swollen lymph nodes; Immune system has been compromised; This is a spontaneous report from a contactable other hcp.  A 24-years-old male patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection, Batch/Lot Number: not reported; Expiry Date: unknown), dose 1 via an unspecified route of administration, administered in Arm Left on 23Jun2021 at 15:45 (at the age of 24-years-old) as dose 1, single for covid-19 immunisation. Medical history included autism spectrum disorder. There were no concomitant medications. Family medical history relevant to ae was none. History of all previous immunization with the Pfizer vaccine considered as suspect was provided as no.' No additional Vaccines Administered on same date of the Pfizer Suspect. The patient experienced swollen lymph nodes on 29Jun2021, and immune system has been compromised on Jun2021. The patient underwent lab tests and procedures on 29Jun2021 which included blood test: unknown, tuberculin test: unknown. This case was reported by a nurse for her son. It was reported that the patient. On 29Jun2021 received and MMR vaccine to fulfill college requirements. He was told at this appointment that he had swollen lymph nodes and was advised to wait for 2 weeks after his originally scheduled (14Jul2021) second Pfizer Covid vaccine dose. This would place his second Pfizer Covid vaccine dose at a 5 week interval, and not a 3 week interval. The caller wanted to know what are the implications of receiving an MMR vaccine in between the Pfizer Covid vaccine doses. Caller wanted to know how the effectiveness of the vaccine would be if her son waited an additional 2 weeks to get the second dose of the vaccine and if there are recommendations for treatment of his side effect (swollen lymphnodes) in the interim. Upon follow-up on 29Jun2021, new information were provided. Reporter specified herself as a Registered Nurse. It was confirmed that the report was not related to any study or programme. NDC number of Pfizer Covid 19 vaccine was unknown. Caller did not have the vaccine card and did not have in-formation about lot number to provide. Investigation Assessment was not provided. With the swollen lymph nodes, the immune system was compromised, and she assumes it was the effect of the DNA. The reporter thought that it was very specific to have in that window between the two dose of the vaccine, otherwise, the second shot may not be going to be effective. The patient was told to wait 2 weeks later than originally scheduled for the second shot. She has no idea what the implications this vaccinations has during this time. It was said that said that the lymph nodes were all enlarged because the immune system was compromised. After vaccination, patient went to the doctor today, instead of getting an MMR titer, he got the MMR vaccination. After that, they told him his lymph nodes were all enlarged and told him to get the second Pfizer shot later. The MMR shot was given between the 2 doses of the Covid vaccine.  The patient went to an urgent care in withheld for his physical for college. They are now telling him to come back Thursday because they didn't do blood work. He is in the doctors office now. They noticed today during his evaluation and Swollen lymph nodes have stayed the same. The doctor told him to wait. Why did they give him the MMR? It doesn't sit well with her. The Pfizer expert told him to wait 2 weeks outside the window. Some people don't practice within their scope. The reporter can't believe they gave him the MMR, he has a developmental disability. It just shows that he has a compromised immune system. She thinks it is in response to the Pfizer.  The reporter informed that it is good that the body is responding in some way. It is the body building immunity, she would think. Is supposed to go back 14Jul2021 for the second one. The doctor said to call Pfizer to see if it is acceptable to push it back 2 weeks. Causality as reported was related and reports it is the bodys response to developing immunity. The patient was given a TB test. Does not know why they didn't do a titer. MMR vaccine name/NDC, LOT, EXP unknown as reporter did not have that information right now. Outcome of the event swollen lymph nodes was not recovered and outcome of the immune system has been compromised was unknown.   Information on the lot/batch number has been requested.