Severe Rhabdomyolysis Temporally Associated with sars-cov-2 Vaccine in an Adolescent

Introduction: Serious pediatric systemic adverse events following receipt of the messenger ribonucleic acid (mRNA) vaccines such as Pfizer/BioNTech vaccine (BNT162b2_V) are rare, with the most common being myocarditis. We report a case of severe rhabdomyolysis following receipt of BNT162b2_V and review the literature for reports in children. To our knowledge, this is the first case of severe rhabdomyolysis temporally associated with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccine in a healthy adolescent without a predisposing cause.

Case Description: A previously healthy16-year-old female developed extensive and severe myalgias and generalized weakness following dose two of BNT162b2_V. She had severe rhabdomyolysis with a peak creatinine kinase (CK) of 246,900 U/L at 92 hours post-vaccination. SARS-CoV-2 polymerase chain reaction (PCR) testing and antibody to nucleocapsid were negative. Extensive workup revealed no alternative causes. The patient was treated effectively with intravenous hyperhydration over a 3-day hospital admission.

As of July 9th, 2021, four pediatric cases of rhabdomyolysis temporally associated with SARS-CoV-2 vaccination were identified in the Vaccine Adverse Event Reporting System (VAERS) database. Case 1 was a 17-year-old male with drug overdose (loratadine and doxylamine) 5 days post dose two of BNT162b2_V. He was found to have rhabdomyolysis and myocarditis. Case 2 was a 12-year-old female with bilateral arm weakness post dose two of BNT162b2_V and a peak CK of 7000 U/L. Rigorous exercise was implicated as a cause in this case. Case 3 was a 14-year-old female who accidently received a triple BNT162b2_V dose (undiluted dose) and developed chest pain, her CK was 7000 U/L. Case 4 was a 14-year-old male who developed myalgias post dose one of BNT162b2_V and had mild rhabdomyolysis with a CK of 1600 U/L.

Discussion: Rhabdomyolysis has been reported following vaccines including BNT162b2_V but without a causal link. Although our case is the fifth adolescent reported, our case is unique given the absence of an identifiable trigger and the severity of rhabdomyolysis. The development of symptoms in close proximity to vaccine administration and in the absence of another identifiable trigger raises concerns about a potential link. Although exaggerated immune response in vaccine recipients who have had previous SARS-CoV-2 infection has been postulated, the absence of nucleocapsid antibodies does not support this in our patient. Immune mediated or aberrant autoimmune responses to adjuvants in the SARS-CoV-2 vaccine, as seen in the autoimmune inflammatory syndrome induced by adjuvants (ASIA) is another possibility. Post-vaccination autoimmune phenomena have been documented in connection to various vaccines.

Conclusion: As more healthy adolescents with robust immune systems become vaccinated, it is important for clinicians to identify rhabdomyolysis post- SARS-CoV-2 vaccination to allow for timely intervention and prevent adverse outcomes such as acute kidney injury.