had been very sick for a day and half after her vaccination; basically crying continuously for 36 hours; getting no sleep; did not want to eat/ baby had shown little interest in eating, in breast feeding; she was just throwing up; she was just really uncomfortable; suspected that she had serious like body ache and pains like get with the flu, but she was 3 months old; suspected that she had serious like body ache and pains like get with the flu, but she was 3 months old; Fever; Cranky and fuzzy; 3-month-old female patient received RSV vaccine; 3-month-old female patient received RSV vaccine; This is a spontaneous report received from a non-contactable reporter (Consumer or other non HCP).  A 3-month-old female patient (unknown if pregnant) received rsv vaccine prot.subunit pref 2v (ABRYSVO), as dose number unknown, single (Batch/Lot number: unknown) at the age of 3 months for immunisation. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: ILLNESS (non-serious), outcome "unknown", described as "had been very sick for a day and half after her vaccination"; CRYING (non-serious), outcome "unknown", described as "basically crying continuously for 36 hours"; INSOMNIA (non-serious), outcome "unknown", described as "getting no sleep"; POOR FEEDING INFANT (non-serious), outcome "unknown", described as "did not want to eat/ baby had shown little interest in eating, in breast feeding"; INFANTILE VOMITING (non-serious), outcome "unknown", described as "she was just throwing up"; DISCOMFORT (non-serious), outcome "unknown", described as "she was just really uncomfortable"; PAIN (non-serious), INFLUENZA LIKE ILLNESS (non-serious), outcome "unknown" and all described as "suspected that she had serious like body ache and pains like get with the flu, but she was 3 months old"; PYREXIA (non-serious), outcome "unknown", described as "Fever"; FEELING ABNORMAL (non-serious), outcome "unknown", described as "Cranky and fuzzy"; OFF LABEL USE (non-serious), PRODUCT USE ISSUE (non-serious), outcome "unknown" and all described as "3-month-old female patient received RSV vaccine". Additional information: The patient's nanny reported that the patient had a very strong reaction to her vaccine, which what she thought was likely she was a very small 3 months old, that they needed to look at her weight and the dosage. She thought this was "kind of a high dose for baby so small." Accordingly to the reporter, this vaccine seemed to be a much stronger reaction for her, but the patient's mother had the information in terms of taking her temperature, in terms of what time she got her vaccine, and what time she started facing symptoms, the detailed information and the patient's mom was going to call later on with higher priority for the baby to go to the doctor. There was no way to know if it was too high of a dose, since it was a pharmacy accident. After few hours having the vaccine, the baby began to cry, she had not stopped for 36 hours. She was crying, unable to eat, she was just throwing up. She was just not interested in eating. The patient showed fever, her temperature had been taken a few times and she was miserable. The reporter just suspected that she had serious like body ache and pains like get with the flu, but she was 3 months old. The baby could not tell what she was feeling; it was a guess. She was fine constantly and she was not interested in eating. She was cranky and fuzzy. She was clearly uncomfortable. That was all. At the time of the report, the reporter thought they had to get the baby into a doctor just for the doctor to verify there was not an allergic type of the reaction. The reporter thought it was like when having the first COVID vaccine and had just felt sick, she thought that was what the baby had been going through. Vaccine name was further reported as "the infant vaccine for RSV by Pfizer." The reporter further stated that probably, the baby had her vaccine at the Pediatrician, not at the pharmacy.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.