This spontaneous report was received from an infectious disease physician referring to a 13-month-old male patient. The patient had no pertinent medical history and was not taking any concomitant medication. The patient had no known drug allergies. On 28-APR-2017, the patient was vaccinated with the first dose of VARIVAX with lot # M042495, 0.5 ml in the left thigh (strength, route of administration and expiration date were not reported) for prophylaxis. On 14-MAY-2017, the patient was admitted to the hospital in the intensive care unit (ICU) due to a sepsis with "group A strep" (streptococcal sepsis) and because of "group A step" septic shock. On 15-MAY-2017, he was treated with Intravenous immunoglobulin (IVIG), as well as had need oxygen therapy and a blood transfusion. Also, it was reported that the patient was under numerous medications due to the streptococcal sepsis. On 06-JUN-2017, the patient's body temperature was 38.4 centigrade degrees (° C). On the same date, the physician noted that the patient developed 8 lesions, small (2 mm) slightly erythematous papules and papulopustular in the left arm, brow, left leg, right arm, and right leg scalp, what appeared to be varicella lesions, which had now scabbed over. The physician requested PCR testing to assist in determining if the lesions were related to wild-type varicella. On 08-JUN-2017 and 09-JUN-2017, a skin biopsy was collected from the skin vesicle/lesion, the result was still pending. Additionally, it was stated that the patient did not have recent Varicella zoster virus (VZV) exposure to chickenpox neither to shingles. Besides, it was reported that the patient was previously healthy and that he had never had chickenpox, history of herpes zoster and he did not have a history of herpes zoster ophthalmicus. At the time of reporting the patient had not recovered from the event streptococcal sepsis, but, he had recovered from varicella. It was unknown if the patient recovered from the septic shock. The events of streptococcal sepsis and varicella were considered as life threatening and disability events by the reporter. The causal relationship between the events and the therapy with VARIVAX was not reported. Upon internal review streptococcal sepsis, septic shock and varicella were considered to be medically significant events. Follow up information was received from the physician on 14-JUN-2017. On an unspecified date in June 2017 reported as "prior to developing the Varicella lesions", the patient was intubated. Additionally, on an unspecified date in June 2017, a swab sample was obtained from the patient's lesions which later in the hospital laboratory was found to be Varicella zoster virus (VZV) positive. This sample was maintained in viral media and stored in the refrigerator. At the time of reporting, the patient did not have any additional lesions to sample, but he had a few scabs. The reporting physician did not think that there were bronchoalveolar lavage samples available for analysis. Follow-up information has been received from the physician on 16-JUN-2017. It was reported that on 28-APR-2017, the patient was seen for a well-child exam and besides VARIVAX, he was also vaccinated with M-M-R II with lot # M034387 and expiration date on 19-JUL-2018 (strength, dose, route of administration or anatomical location were not provided), and VAQTA with lot # M039202 (expiration date, strength, dose, route of administration or anatomical location were not provided), both for prophylaxis. On 06-MAY-2017, the patient developed fever which reportedly lasted for 4 days. The patient had three visits to the pediatrician's office and was admitted to the intensive care unit (ICU) on 14-MAY-2017 with Group A Streptococcal (Strep) sepsis. In the morning of 07-JUN-2017, the physician noticed the patient's first lesions and he developed a total of 8 lesions. It was reported that the patient's samples were shipped on 15-JUN-2017. She confirmed that 2 packages were sent since one was sent frozen for delivery on 16-JUN-2017. At the time of this report, the patient was recovering from the group A Streptococcal sepsis and Streptococcal septic shock as it was stated that he was doing much better, and that even though the patient was still hospitalized in the ICU, he was waiting to be transferred to a rehab facility maybe later on 16-JUN-2017. The causal relationship between the events with M-M-R II and VAQTA was not reported. Additional information has been requested.