maternal exposure during breast feeding; rash to face, hands, abdomen/ erythomatous papules; Doctor reported that the rash sample from the mother identified vaccine strain VZV; This spontaneous report was received from a physician and refers to a female, 40-year-old patient. Her medical history included pre-eclampsia, pregnancy, concurrent condition included breast feeding. She was healthy, did not have recent varicella zoster virus (VZV) infection or exposure to herpes zoster, herpes zoster ophthalmicus, chickenpox or shingles. No known drug allergies (NKDA). The patient did not receive any concomitant therapies. On 19-DEC-2020, the patient delivered a female baby with no congenital anomalies. Approximately last menstrual period (LMP) was on 14-MAR-2020 and the date of conception was established as approximately 28-MAR-2020.  On 20-DEC-2020, the patient was vaccinated with varicella virus vaccine live (oka/merck)(VARIVAX) 0.5 ml, in right arm, lot # T020652, upon internal validation was determined to be a valid lot #, expiration date was not reported but established as 16-JUN-2022 (strength and route of administration were not reported) since it was determined during a prenatal screen, that she was not immune to varicella (for prophylaxis). The physician was not sure, if the baby was in close contact or in the room at the time the patient was vaccinated. No rash occurred at the site of injection following the vaccination.  On approximately 09-JAN-2021- 11-JAN-2021, also reported as day 21-23 post-vaccination, the patient (mother) developed a rash (vesicles) to face, hands and abdomen, less than 10 lesions (also reported as less than 50). The rash was also described as erythematous papules, no vesicles (inconsistency). She was afebrile. The baby was breastfeeding at the time the patient had developed a rash, and was switched to formula on an unknown date in January 2021 (reported also as shortly thereafter) (maternal exposure during breast feeding).  It was not specified if the patient was breast feeding before rash. The physician wanted to send viral isolates. Since 11-JAN-2021, the patient had no new lesions (dried up). She did not receive any treatment. On 20-JAN-2021, the sample scab from the patient's abdomen was collected.  The patient was enrolled in the Varicella Zoster Virus Identification Program to identify if VZV was present and if it was present, to identify if it was associated with the wild-type (WT) VZV strain or with the Oka/Merck vaccine strain.  On 19-JAN-2021, the call was made to physician to confirm receiving requested program information. The physician was not sure, if they would send samples to disease control or another lab or if would participate in the Varicella Zoster Virus Identification Program (VZVIP), since the physician would need to discuss further with the manager. The program information was e-mailed to the physician as requested. The physician had additional questions upon receipt of the program information and an additional phone call was made. Upon speaking with the physician during the second call, the reporter stated, that they would like to send samples through the VZVIP. Detailed shipping instructions were provided.  On 20-JAN-2021, a call was made to the physician to help arrange for the shipping of samples. On that day, the specimen sample was collected from the patient's right foot vesicle/lesion. The physician confirmed, that there would be four total samples sent: 3 samples from the baby and 1 lesion scab from the mother's (patient's) abdomen. The call concluded with discussion that all four samples would be picked up by the courier by the end of business.  On 25-JAN-2021 it was confirmed by the physician, that the 3 patient's specimens were sent to the laboratory on 20-JAN-2021. The samples were delivered. The results were still not obtained. Additional information has been requested.  On 31-JAN-2021, a notification was received from the Varicella Zoster Virus Identification Program (VZVIP) laboratory physician and reported that the samples from the patient and the patient's baby arrived to the laboratory on 22-JAN-2021 and on an unspecified date in January 2021 were confirmed as positive for Oka Vaccine Strain. On 01-FEB-2021, the PCR results were reviewed with the patient's physician who confirmed that.  Telephone call on 04-FEB-2021 was made to provide results of the report received from the physician for the PCR analyses processed through the VZVlP for both the patient and the baby. It was informed by other physician, that the patient's scab sample confirmed the presence of varicella-zoster virus and was identified to be Oka vaccine strain. The physician stated, that both mom (patient) and baby were doing well and were scheduled for follow-up visit on 08-FEB-2021. Additional information has been requested. The outcome of the event of erythropapular rash was recovered on an unspecified date in 2021. The outcome of varicella zoster virus DNA test positive was not reported. The causality between the suspect vaccine and the events was not provided.  This is one of the two linked reports of mother and child (the baby's case # 2101USA009684).; Sender's Comments:  US-009507513-2101USA009684: