Initial unsolicited report received from the literature on 23 May 2016. Abstract: Background: Measles is resurging, with more than 700 confirmed cases since January 2014. During measles outbreaks, vaccination as early as at 6 months of age is sometimes recommended for infants who are at risk for exposure. Methods: We searched the Vaccine Adverse Event Reporting System for reports of measles, mumps, and rubella vaccine combined (MMR) or measles, mumps, rubella, and varicella vaccine combined (MMRV) vaccination in children less than 9 months of age. We performed a clinical assessment of each report and summarized the frequency, range, onset time, and severity of adverse events. Results: After excluding 346 reports because they were duplicates or because they contained insufficient information about the child's age or vaccine(s), we retained 204 reports in the analysis, including 35 (17%) that were serious. Among the 169 non-serious reports, more than half (88; 52%) described a vaccination error without any adverse event per se. Other non-serious reports described fever, injection reactions, and gastrointestinal symptoms. Serious adverse events included developmental disorders, fever, and fussiness. There were 44 reports of fever, but only 4 cases began 5-12 days after immunization, the peak risk window. The vast majority of fever reports listed concomitant vaccines, such as diphtheria and tetanus toxoids, acellular or whole-cell pertussis vaccine. Conclusions: This review did not identify any major safety concerns. These findings may facilitate discussions about the risks and benefits of vaccinating infants who are potentially exposed to this life-threatening disease. This case involves a three-month-old male patient who was vaccinated with a dose of DIPHTHERIA, TETANUS AND PERTUSSIS VACCINE (ADSORBED) (DTP) (manufacturer: unknown, batch number, expiration date, dose, route and site of administration were not reported) and a dose of MEASLES, MUMPS AND RUBELLA VACCINE (MMR) (manufacturer: other, batch number, expiration date, dose, route and site of administration was not reported) both on an unspecified date. The patient had no significant past medical history. Concomitant medications were not reported. On an unspecified date, same day (reported as within one day) following vaccination, the patient had experienced congestion and fever (temperature not specified). On the following morning, one day post vaccination, the patient was found pulseless, apneic. An autopsy was not performed, but the death certificate listed sudden infant death syndrome (SIDS) as the cause of death. Laboratory investigations and corrective treatment were not reported. The outcome of the events congestion and fever was not reported. List of documents held by sender: none. Sender's Comments: In this case from medical literature, the 3-month-old patient died due to sudden infant death syndrome (SIDS) 2 days after having received vaccination with DTP and MMR. The reason for early administration of MMR was not stated. SIDS was considered as the cause of death in the death certificate though autopsy was not performed. The patient had developed fever and some unspecified congestion the next day after receiving the vaccines which could suggest the possibility of underlying infection. This case is insufficiently documented to draw a conclusion on a relationship with vaccine administration. Most frequent causes of sudden death in infants include infections, sudden infant death syndrome, inherent errors in metabolism, undiagnosed congenital anomalies. No information is provided on conditions at the time of death, sleeping position, patient's history, previous vaccination history, autopsy or results of investigations; if performed in hospital. Moreover, the patient received two vaccines simultaneously making it difficult to assess the role of one vaccine in particular. Reported Cause(s) of Death: sudden infant death syndrome (SIDS).