Vaccine exposure via breastmilk; after the second dose she started becoming more congested and having respiratory symptoms; I''ve been exclusively breastfeeding my daughter since she''s been born. After receiving the vaccine she started acting different - difficult sleeping, more irritable and then after the second dose; I''ve been exclusively breastfeeding my daughter since she''s been born. After receiving the vaccine she started acting different - difficult sleeping, more irritable and then after the second dose; after the second dose she started becoming more congested and having respiratory symptoms; This is a spontaneous report received from a contactable reporter(s) (Other HCP). The reporter is the parent.  A female patient was exposed to bnt162b2 (BNT162B2), transmammary (Batch/Lot number: unknown) as dose number unknown, single for covid-19 immunisation. The mother of the patient was 30 year-old. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: NASAL CONGESTION (non-serious), RESPIRATORY SYMPTOM (non-serious) all with onset 05Sep2021 05:00, outcome "not recovered" and all described as "after the second dose she started becoming more congested and having respiratory symptoms"; INSOMNIA (non-serious), IRRITABILITY (non-serious) all with onset 05Sep2021 05:00, outcome "not recovered" and all described as "I''ve been exclusively breastfeeding my daughter since she''s been born. After receiving the vaccine she started acting different - difficult sleeping, more irritable and then after the second dose"; EXPOSURE VIA BREAST MILK (non-serious), outcome "unknown", described as "Vaccine exposure via breastmilk". The events "after the second dose she started becoming more congested and having respiratory symptoms", "i''ve been exclusively breastfeeding my daughter since she''s been born. after receiving the vaccine she started acting different - difficult sleeping, more irritable and then after the second dose", "i''ve been exclusively breastfeeding my daughter since she''s been born. after receiving the vaccine she started acting different - difficult sleeping, more irritable and then after the second dose" and "after the second dose she started becoming more congested and having respiratory symptoms" were evaluated at the physician office visit. Therapeutic measures were not taken as a result of nasal congestion, insomnia, irritability, respiratory symptom.  Additional information: Mother stated that patient started becoming more congested and having respiratory symptoms. These have persisted for the last 2 months, and we were still battling them. When she gave her daughter frozen breast milk pumped before she received the vaccine her symptoms become better. Each time she seemed she was recovering, it got worse again. When shed nurse her, she got worse again. If covid prior vaccination: Yes, If covid tested post vaccination: No, Known allergies: No, Other medical history: No. Mother received COVID 19 Vaccine dose 1 in left arm on 09Aug2021 at 07:30 am (lot number: Ew0186) and dose 2 in left arm on 02Sep2021 at 07:30 am (lot number: Ew0186).  Follow-up attempts completed. No further information is expected. The lot/batch number is not available despite the follow-up attempts made.