Neonatal mortality—death that occurs during the first 28 days of life—accounts for nearly half of all the deaths that occur in children before they reach their fifth birthday. Worldwide, nearly 3 million neonatal deaths occur every year. Three bacterial infections—sepsis (infection of the bloodstream), pneumonia (infection of the lungs), and meningitis (infection of the brain's protective covering)—are responsible for nearly a quarter of all neonatal deaths. Babies born in low- and middle-income countries (LMICs) are at particularly high risk of developing neonatal bacterial infections because the risk factors for these infections, which include maternal infections and unhygienic delivery care, are more common in LMICs than in high-income countries. Babies born in LMICs are also at a high risk of dying from bacterial infections because access to appropriate medical care and antibiotics is often poor.